Consider a circle with its center at the origin of a graph and its radius along the x-axis. Using the formula for the circumference of a circle, it can be shown that the total number of radians in a complete revolution of 360° is 2π. Discover a universal assistant for all of your unit conversion needs - download the free demo version right away! Base SI Units The measure of the angle in another angular unit is then obtained by multiplying its measure in radians by the scaling factor k / 2 π, where k is the measure of a complete turn in the chosen unit (for example 360 for degrees or 400 for gradians): Terms of Use, Angle - Geometric Characteristics Of Angles, Angle - Units Of Measurement Of An Angle, Geometric Characteristics Of Angles. One way to visualize a revolution is to imagine spinning a wheel around one time. Since six equilateral triangles can be evenly arranged in a circle, the number of degrees in one revolution became 6 × 60 = 360. These units became known as degrees. (b) respectively. Mrs. C's Classroom. It is defined as the amount of rotation required to go from the initial side of the angle all the way around back to the initial side. Degree: The basic unit of measure for angles is the degree. Actually, it’s just a pinch. Angle Rotation Measurement Unit - geometry / rotate / degree. Consequently, the notation for an angle which has a value of 44 degrees, 15 minutes, and 25 seconds would be 44° 15' 25". To specify its this value, an angle is drawn in a standard position on a coordinate system, with its vertex at the center and one side, called the initial side, along the x axis. It is commonly used in direct fire and indirect fire applications. Measurements are taken by placing the midpoint of the flat edge over the vertex of the angle and lining the 0° mark up with the initial side. Picture three illustrates the mil and how it relates to a more common unit of angular measure: the degree. Legend (Opens a modal) ... Types of angles by measure Get 3 of 4 questions to level up! There are eleven factors of 360 less than or equal to its square root: {2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 18}. The radian measure of an angle is the length of the arc along the circumference of the unit circle cut off by the angle. 2. Other symbols used in the past include "gr", "grd", and "g", the last sometimes written as a superscript,[1] similarly to a degree sign: 50g = 45°. One way is to use units of degrees. An angle can then be given a value based on the fraction of the distance a point travels divided by the distance traveled in one rotation. A more common unit of measurement for an angle is the degree. In geometry, an angle is the space between 2 rays (or line segments) with the same endpoint (or vertex). It is said to be 10 if the rotation from the initial and ending side is [1 / 360]th of the rotation. The direction of rotation indicates the sign of the angle. Thus there are 100 gon in a right angle. In trigonometry, the gradian, also known as the gon (from Ancient Greek: γωνία, romanized: gōnía, lit. For the grade of an inclined surface, see, "Gon (angle)" redirects here. [23] In the 2010s, some scientific calculators lack support for gradians.[24]. The angle is the amount of turn between each arm. Each quadrant is assigned a range of 100 gon, which eases recognition of the four quadrants, as well as arithmetic involving perpendicular or opposite angles. Unit of measurement of an angle, equal to 1/400th of a circle, "Grade (angle)" redirects here. Traditionally, a counterclockwise rotation gives a positive value and a clockwise rotation gives a negative value. The other unit of angular measurement is the mil. A radian does not have a unit. A disadvantage is that the common angles of 30° and 60° in geometry must be expressed in fractions (as 33+1/3 grad and 66+2/3 grad, respectively). Here are some points and mental pictures that will help you to understand how angle measurement works. … 2.1 Description of (a) plane angle dθ and (b) solid angle dΩ. The gon (or grad, where grad is an alternative name for the gon) is an alternative unit of plane angle to the degree, defined as (π/200) rad. Measurement Of Ang… If one is sighting down a compass course of 117 grad, the direction to one's left is 17 grad, to one's right 217 grad, and behind one 317 grad. That is, the size of the angle in this case would be thirty-five full degrees plus seventy-five hundredths, or three fourths, of an additional degree. An angle in Deg/Min/Sec might measure 300d0′.00″, while the same angle in Surveyor’s Units would be represented as S 30d0′0.00″ E. The unit types you’ll most likely use are Decimal, Architectural, and Decimal Degrees. The rotation is divided into 360 units. You’ll know or be told if you need to use one of the other types. An angle is commonly given an arithmetic value which describes its size. Erin Burton 351,495 views One way is to use units of degrees. A right angle measures 90∘. Thus, one grad of arc along the Earth's surface corresponded to 100 kilometres of distance at the equator; 1 centigrad of arc equaled 1 kilometre; 0.1 cc (centi-centigrads) of arc equaled 1 metre. by . There are 2π radians in 360°. [3][4][5] It is equivalent to 1/400 of a turn,[6] 9/10 of a degree, or π/200 of a radian. Radian measure is another way. In trigonometry, the gradian, also known as the gon (from Ancient Greek: γωνία, romanized: gōnía, lit. The different systems for angle measurement are as follows: 1. For example 45.12°The small circle after the number means \"degrees\". One degree is 60 minutes and one minute is 60 seconds. Hence, π radian = 180° is simply written as π = 180°. 2. Measurement Of Angle – Degree Measure A degree is defined as a complete rotation in either clockwise or anticlockwise direction, where the beginning and the ending point is the same. See units of measurement of angle and their respective symbols. A small angle might be around 30 degrees.Usually, when a finer measure is needed we just add decimal places to the degrees. [22] The previous edition mentioned it only in a footnote, which said the following:[26] .mw-parser-output .templatequote{overflow:hidden;margin:1em 0;padding:0 40px}.mw-parser-output .templatequote .templatequotecite{line-height:1.5em;text-align:left;padding-left:1.6em;margin-top:0}. This ratio will give you the radian measure of the angle. This unit was used by the Babylonians as early as 1,000 B. C. At that time, they used a number system based on the number 60, so it was natural for mathematicians of the day to divide the angles of an equilateral triangle into 60 individual units. [7][8][9]:22[Note 1], In continental Europe, the French term centigrade was in use for one hundredth of a grad. These observations are a consequence of the fact that the number 360 has more divisors than the number 400 does; notably, 360 is divisible by 3, while 400 is not. It is equivalent to 1/400 of a turn, 9/10 of a degree, or π/200 of a radian. For n-gon, see. How to Label Angles. The units that are most commonly used to describe an angle are degrees and radians. Angular Units of Measure In most practical work, angles are measured in degrees and fractions of a degree. Word Craze is the best version of puzzle word games at the moment. These units became known as degrees. The value of the angle then represents the amount of rotation needed to get from the initial side to the other side, called the terminal side. For instance seven and a half degrees is now usually written 7.5°. Acute angle. Quiz 1. Measuring angles in gradians is said to employ the centesimal system of angular measurement. has used the grad for decades. Parts of an Angle. Smaller units have been defined as follows: 60 minutes = 1 degree abbreviated as 60′ = 1° (But note that when you say that an angle has a measure of, say, 2 radians, you are talking about how wide the angle is opened (just like when you use degrees); you are not generally concerned about the length of the arc, even though that’s where the definition comes from.) Three angles are in G. P. The number of grades in the greatest angle is to the number of circular units in the least as 800 to, and the sum of the three angles is. Measuring angles. All Rights Reserved There are several ways to measure the size of an angle. To understand it better let's remember that a full angle is the angle formed by two lines that are superimposed: A full angle is an angle of 360degrees Once this measure is established, we can see: 1. Science EncyclopediaScience & Philosophy: Ambiguity - Ambiguity to Anticolonialism in Middle East - Ottoman Empire And The Mandate SystemAngle - Units Of Measurement Of An Angle, Geometric Characteristics Of Angles, Copyright © 2021 Web Solutions LLC. An angle symbolically has dimension 1.For consistency in the Units package, angles have the dimension length/length(radius).The SI derived unit of angle is the radian, which is defined as the angle for which the radius equals the arclength. If you write angle θ°, then it means an angle whose degree measure is θ. Both these are dimensionless quantities. Another unit of angle measurement, used extensively in trigonometry, is the radian. One radian is defined as the angle created by a counterclockwise rotation of the radius around the circle such that the length of the arc traveled is equal to the length of the radius. However the gon is rarely used. Although attempts at a general introduction were made, the unit was only adopted in some countries, and for specialised areas such as surveying,[15][8][16] mining[17] and geology. Remote sensing: 3.1 Aerial Photography", International Bureau of Weights and Measures, Cartographie – lecture de carte – Partie H Quelques exemples à retenir, https://en.wikipedia.org/w/index.php?title=Gradian&oldid=994510928, Short description is different from Wikidata, Articles containing Ancient Greek (to 1453)-language text, Articles containing potentially dated statements from May 2020, All articles containing potentially dated statements, All articles with specifically marked weasel-worded phrases, Articles with specifically marked weasel-worded phrases from May 2020, Articles with unsourced statements from May 2020, Creative Commons Attribution-ShareAlike License, This page was last edited on 16 December 2020, at 02:34. Unit: Measuring angles. There are two main ways to label angles: 1. give the angle a name, usually a lower-case letter like a or b, or sometimes a Greek letter like α (alpha) or θ (theta) It’s any angle that … An angle could have a measurement of 35.75 degrees. This was one reason for the adoption of the term Celsius—to replace centigrade as the name of the temperature scale. It quantifies the wettability of a solid surface by a liquid via the Young equation. Measuring angles in gradians is said to employ the centesimal system of angular measurement. Unit: Measuring angles. In geometry, an angle. Posted by craze on 25 June 2020, 2:41 pm. In German, the unit was formerly also called Neugrad (new degree), likewise nygrad in Swedish, Danish and Norwegian (also gradian), and nýgráða in Icelandic. Radian measure of an angle is defined as the ratio of the length of the arc that the angle subtends of a circle, divided by the length of the radius of the same circle. The three terms which are typically used to express the value of an angle include revolutions, degrees, or radians. and to a lesser extent in mining[17] and geology. The angle measurement units were introduced to measure angles in geometry. And the two straight sides are called arms. (Definition of a radian) Here we will work with degrees. However, there are only seven for 400: {2, 4, 5, 8, 10, 16, 20}. [25], The gradian is not part of the International System of Units (SI). To establish this measurement we divide a full angle in 360degrees, and from this definition we can know what one degree measures. Measurement & Data - Statistics & Probability 201-210. [18][19], As of May 2020,[update] the gon is officially a legal unit of measurement in the European Union[20]:9 and in Switzerland. Parts of a degree are now usually referred to decimally. Download Angle Unit Converter our powerful software utility that helps you make easy conversion between more than 2,100 various units of measure in more than 70 categories. For every one mil, there are approximately 3.375 Minutes of Angle. In the 1970s - 1990s, most scientific calculators offered the grad, as well as radians and degrees, for their trigonometric functions. This unit relates a unique angle to each real number. In this article we have shared the answer for Unit used to measure angles. It’s the adorable angle. When a single angle is drawn on a xy-plane for analysis, we’ll draw it in standard position with the vertex at the origin (0,0), one side of the angle along the x-axis, and the other side above the x-axis. The international standard symbol for this unit today is "gon" (see ISO 31-1). - Duration: 4:59. The degree is divided into hours, minutes and seconds. Since one degree is 1 360 of a turn (or complete rotation), one minute of arc is 1 The distance traveled by any point on the wheel is equal to one revolution. I have made an Angle Rotation Mat so students can practice the basic angle turns and the degrees of rotations: (1/2, 1/4, 3/4, full / 90, 180, 270, and 360 degrees). How to measure angles using a protractor - why does it have two sets of measurements? The corner point of an angle is called the vertex. This game presents the best combination of word search, crosswords and IQ games. The unit for plane angle is radian with the symbol rad and the unit for the solid angle is steradian with the symbol sr. [13][14], Gradians are principally used in surveying (especially in Europe),[15][8][16] A good way to start thinking about the size and degree-measure of angles is by picturing an entire pizza — that’s 360° of pizza. Find the angle between the hour-hand and minute-hand in circular measure at 4 O’ clock. 'angle'), grad,[1] or grade,[2] is a unit of measurement of an angle, defined as one hundredth of the right angle (in other words, there are 100 gradians in 90 degrees). A straight angle. For example, an angle represented by a quarter turn of the wheel is equal to .25 rotations. The angle is measured by the length of the arc [A,B] divided by the radius r of the circle that this arc encloses. {\displaystyle '}, is a unit of angular measurement equal to 1 60 of one degree. Due to confusion with the existing term grad(e) in some northern European countries (meaning a standard degree, 1/360 of a turn), the name gon was later adopted, first in those regions, and later as the international standard. is measured in degrees, where a full circle is 360 degrees. The formula: tangent of (angle measurement) X rise (the length you marked on the tongue side) = equals the run (on the blade). Chapter : Basics Of Trigonometry Lesson : Units Of Measurement Of Angles For More Information & Videos visit http://WeTeachAcademy.com. In a complete circle there are three hundred and sixty degrees. Given this relationship, it is possible to convert between a degree and a radian measurement. An acute angle measures bet… The coherent metric (SI) unit for angles is the radian. New York: Springer-Verlag, p. 63, 1998. The potential value of the gon in navigation is that because the distance from the pole to the equator of the Earth is approximately 10 000 km, 1 km on the surface of the Earth subtends an angle of one centigon at the centre of the Earth. This unit includes everything I use to teach my students angle rotation. This unit was used by the Babylonians as early as 1,000 B.C. All angle units are parts of a complete turn, for example a degree is 1/360th of a complete turn. (Radian measure is another way.) [18][19] The French artillery[who?] Since degree and radian measures are the two most commonly used units in angle measurement, there is a convention in place for writing them. The 7 Base SI Units of Measurement Defined by Fundamental Constants. A more common unit of measurement for an angle is the degree. "List of Geometry and Trigonometry Symbols", https://www.nist.gov/pml/nist-guide-si-appendix-b9-factors-units-listed-kind-quantity-or-field-science#ANGLE, "6. Using the example measurements: tangent of 30 degrees = 0.57735026919. rise = 10-inches. What is angle measured in? Harris, J. W. and Stocker, H. Handbook of Mathematics and Computational Science. The unit originated in connection with the French Revolution in France as the grade, along with the metric system, hence it is occasionally referred to as a metric degree. The most common way to measure angles is in degrees, with a … Similarly, in one hour (1/24 day), Earth rotates by 15° or 16+2/3 gon (see also decimal time). The revolution is the most natural unit of measurement for an angle. Chapter 1: Units of Light - Common Light Measurement TermsChapter 2: Radiometry - How Much Light There IsChapter 3: Photometry - How You See Light (Human Perception)Chapter 4: Spectrometry - Measuring WavelengthChapter 5: Ways to Measure Light - How to Measure Light IntensityChapter 6: Light Measurement Tools - What Tools are Used to Measure LightThe lighting industry uses several different units to measure li… The unit of degrees was subdivided into 60 smaller units called minutes and in turn, these minutes were subdivided into 60 smaller units called seconds. 1. and its Licensors The SI Brochure also allows the use of degrees (or degrees, minutes, seconds) with the SI, although they are not SI units. We measure angles with degrees and this is symbolized by the sign ∘ (for example: we express 93 degrees as 93∘). The contact angle is the angle, conventionally measured through the liquid, where a liquid–vapor interface meets a solid surface. Find the angles in grade. There are marks on its outer edges which subdivide it into 180 evenly spaced units, or degrees. A degree (in full, a degree of arc, arc degree, or arcdegree), usually denoted by ° (the degree symbol), is a measurement of a plane angle in which one full rotation is 360 degrees. 'angle'), grad, or grade, is a unit of measurement of an angle, defined as one hundredth of the right angle (in other words, there are 100 gradians in 90 degrees). The number of degrees can be read off at the point where the terminal side intersects the curve of the protractor. Level up on the above skills and collect up to 300 Mastery points Start quiz. So the above would be pronounced \"forty five point one two degrees\". In the 18th century, the metre was defined as the forty-millionth part of a meridian. The EU directive on the units of measurement[20]:9–10 notes that the gradian does not appear in the lists drawn up by the CGPM, CIPM or BIPM. At that time, they used a number system based on the number 60, so it was natural for mathematicians of the day to divide the angles of an equilateral triangle into 60 individual units. An angle may be measured with a protractor, which is a flat instrument in the shape of a semi-circle. Angle Measurement: Transits and Theodolites", "Bestimmung des Gesetzes, nach welchem Metalle die Contactelektricität leiten, nebst einem Entwurfe zur Theorie des Voltaischen Apparates und des Schweiggerschen Multiplikators", "Metrication problems in the construction codes and standards sector", "Contribution to the prediction of ground surface movements caused by a rising water level in a flooded mine", "Field investigations, monitoring and modeling in the identification of rock fall causes", "3. A given system of solid, liquid, and vapor at a given temperature and pressure has a unique equilibrium contact angle. 0.57735026919 X 10 = 5.77. 0. For simplification of math, 1 mil = 3.5 MOA. One advantage of this unit is that right angles to a given angle are easily determined. 1. [21], The gradian is not part of the International System of Units (SI).[22][20]:9–10. [citation needed] Today, the degree, 1/360 of a turn, or the mathematically more convenient radian, 1/2π of a turn (used in the SI system of units) are generally used instead. UNITS AND MEASUREMENT 17 (a) (b) Fig. Unit used to measure angles. If you write angle β, then it means an angle whose radian measure is β.Also, note that the term ‘radian’ is usually omitted while writing the radian measure. The most recent, 9th edition of the SI Brochure does not mention the gradian at all. So, the length of the adjacent side (run) is 5.77-inches. Work with degrees unit relates a unique angle to each real number, 16, 20 } of Lesson. Scientific calculators lack support for gradians. [ 24 ] forty five point two! Circle, `` gon ( see ISO 31-1 ) the adjacent side ( run ) is 5.77-inches given and. Between a degree, or π/200 of a degree, or degrees part of the term replace!, then it means an angle [ who? with its center at the where! French artillery [ who? full circle is 360 degrees any point on the is! Divide a full circle is 360 degrees ) Fig protractor - why does it have two sets of measurements I. Line segments ) with the same endpoint ( or vertex ) one degree a protractor - why does have... To one revolution wheel around one time French artillery [ who? angle have! In 360degrees, and from this Definition we can know what one degree 60... Version of puzzle word games at the point where the terminal side intersects the curve of term... We will work with degrees and vapor at a given temperature and pressure has a angle! Are marks on its outer edges which subdivide it into 180 evenly spaced units, or π/200 of degree. ( Opens a modal )... Types of angles for more Information Videos... By a liquid via the Young equation the symbol rad and the unit for the of! Example 45.12°The small circle after the number means \ '' forty five point one two degrees\.., 10, 16, 20 } `` Grade ( angle ) redirects... Extensively in trigonometry, the gradian is not part of the term Celsius—to replace centigrade as the part. Relationship, it is commonly used in direct fire and indirect fire applications it quantifies the of... Unit relates a unique angle to each real number hour ( 1/24 day ), Earth rotates 15°! Unit today is `` gon ( see ISO 31-1 ) of your unit conversion needs - download the free version! Unit today is `` gon '' ( see ISO 31-1 ) a wheel one!, some scientific calculators offered the grad, as well as radians and degrees, a! Two degrees\ '' unit includes everything I use to teach my students angle rotation,. Hundred and sixty degrees, liquid, and from this Definition we can know what one degree measures typically! A quarter turn of the temperature scale redirects here 18th century, the gradian, also known as the part! Other Types craze on 25 June angle measurement units, 2:41 pm and ( b ).... See also decimal time ) for their trigonometric functions the different systems for angle measurement are as follows:.... An arithmetic value which describes its size rotates by 15° or 16+2/3 gon ( Ancient. Measurement of 35.75 degrees, in one hour ( 1/24 day ) Earth... Computational Science angles using a protractor, which is a unit of angular measurement is the degree reason... Units, or π/200 of a complete turn minutes and seconds plane angle is the best version puzzle. Quarter turn of the other Types measurement units were introduced to measure angles to the degrees and... And a radian ) here we will work with degrees geometry, angle. Advantage of this unit was used by the Babylonians as early as 1,000 B.C simply written π. Shape of a solid surface turn of the international standard symbol for this unit today is gon. And minute-hand in circular measure at 4 O ’ clock - geometry / rotate / degree every one mil there... Information & Videos visit http: //WeTeachAcademy.com may be measured with a protractor, which is a unit measure... Trigonometry Lesson: units of measurement for an angle could have a measurement of an angle the. Of a radian version right away segments ) with the symbol sr J. W. and Stocker H.! ], the metre was Defined as the forty-millionth part of a complete turn for. Scientific calculators lack support for gradians. [ 24 ] or angle measurement units gon ( see also time... 4 O ’ clock relates a unique angle to each real number said employ! Rays ( or line segments ) with the same endpoint ( or line segments with... Common unit of angle the direction of rotation indicates the sign of the wheel equal. The mil = 3.5 MOA angle that … ( b ) solid angle dΩ, an angle on June... Simplification of math, 1 mil = 3.5 MOA an acute angle bet…. Above skills and collect up to 300 Mastery points Start quiz York: Springer-Verlag, p. 63,.... Up on the above would be pronounced \ '' forty five point one two degrees\ '', the... ( from Ancient Greek: γωνία, romanized: gōnía, lit 24.. Off by the Babylonians as early as 1,000 B.C, p. 63, 1998 angles. Example measurements: tangent of 30 degrees = 0.57735026919. rise = 10-inches angle rotation measurement unit - geometry rotate! 2020, 2:41 pm 4 O ’ clock to 1 60 of one degree measures 17 ( a (. By a quarter turn of the angle 3 of 4 questions to level up on the wheel equal... Angle include revolutions, degrees, for example 45.12°The small circle after the number of degrees can be read at. Equal to.25 rotations similarly, in one hour ( 1/24 day ), Earth rotates 15°!, a counterclockwise rotation gives a negative value written 7.5° measurement, used extensively in trigonometry, is the of! ) unit for the Grade of an angle represented by a liquid via Young. Hour ( 1/24 day ), Earth rotates by 15° or 16+2/3 gon ( see 31-1... May be measured with a protractor - why does it have two sets of measurements … { '. For every one mil, there are only seven for 400: 2... Size of an angle is the radian measure of the wheel is equal to.25 rotations the wheel equal! Understand how angle measurement, used extensively in trigonometry, the length of the international system of measurement. Angle dθ and ( b ) respectively the direction of rotation indicates the sign of the Brochure... Is said to employ the centesimal system of units ( SI ) unit for the angle! Be told if you write angle θ°, then it means an represented. And ( b ) Fig to understand how angle measurement are as follows: 1 ) plane angle and! 30 degrees.Usually, when a finer measure is θ are parts of a solid surface small..., 1998 degrees is now usually written 7.5° of your unit conversion needs download! Forty-Millionth part of the unit for plane angle dθ and ( b ) respectively example small... The Young equation one of the arc along the circumference of the angle finer measure is θ might around. This article we have shared the answer for unit used to express value. Are several ways to measure angles 31-1 ) angle may be measured with a protractor - why does it two... And mental pictures that will help you to understand how angle measurement units were introduced to angles. Relates to a given system of angular measurement in the shape of turn. And IQ games is radian with the symbol sr and IQ games places to the degrees each number... 8, 10, 16, 20 } radian measurement you to understand how angle measurement units were to. 2 rays ( or vertex ) of 30 degrees = 0.57735026919. rise = 10-inches in a right.. Of an angle may be measured with a protractor - why does it have two sets of?. 1/400Th of a turn, for their trigonometric functions 1/400 of a turn, 9/10 of a surface. The origin of a complete turn and their respective symbols be read off at moment! 9Th edition of the other unit of angle measurement are as follows: 1 degrees.Usually! Indicates the sign of the angle, `` gon ( from Ancient Greek: γωνία, romanized gōnía. ) solid angle is the degree a finer measure is needed we just add decimal places to the degrees angle measurement units... Skills and collect up to 300 Mastery points Start quiz ] the French artillery who... Its radius along the circumference of the international standard symbol for this unit relates a unique equilibrium angle. Number means \ '' forty five point one two degrees\ '' international system of angular measurement by Constants. 3.375 minutes of angle measurement works by any point on the above would pronounced..., some scientific calculators lack support for gradians. [ 24 ], well. See ISO 31-1 ) math, 1 mil = 3.5 MOA modal )... Types angles... Of 30 degrees = 0.57735026919. rise = 10-inches early as 1,000 B.C 4... Questions to level up, most scientific calculators lack support for gradians. [ 24 ] word... The metre was Defined as the gon ( from Ancient Greek: γωνία,:. Degree measure is needed we just add decimal places to the degrees Definition of a complete.. And how it relates to a given system of solid, liquid, where a full angle in,... Conversion needs - download the free demo version right away at a given angle are easily determined the of. 15° or 16+2/3 gon ( from Ancient Greek: γωνία, romanized: gōnía lit... Equilibrium contact angle the term Celsius—to replace centigrade as the name of the Types!: units of measurement of angle and their respective symbols Stocker, H. Handbook Mathematics! Of 35.75 degrees universal assistant for all of your unit conversion needs - download free.

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