Who inVenTEd the RULER?
373706
It was is 2303BC in egypt they used a ruler like stick to measure abd find the length of and record the stars/
486958
Because someone really messed with your ruler.  Or maybe you're just holding it backward ...
93031
Check this out...\n\nhttp://home.inter.net/eds/paper/inchmetric.html
83417
oh, he was a mighty ruler....
1166293
That person must be knowing who invented these words
136243
measuring device of some sort (scale, ruler, thermometer)
156925
the same person who invented the wall-stretcher
82598
alfred wegener\njust learned this myself (:
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Euclid.\nGreek geometer who wrote the Elements , the world's most definitive text on geometry. The book synthesized earlier knowledge about geometry, and was used for centuries in western Europe as a geometry textbook. The text began with definitions, postulates ("Euclid's postulates "), and common opinions, then proceeded to obtain results by rigorous geometric proof. Euclid also proved what is generally known as Euclid's second theorem:  the number of primes  is infinite.  The beautiful proof Euclid gave of this theorem is still a gem and is generally acknowledged to be one of the "classic" proofs of all times in terms of its conciseness and clarity. In the Elements , Euclid used the method of exhaustion and reductio ad absurdum. He also discussed the so-called Euclidean algorithm  for finding the greatest common divisor  of two numbers, and is credited with the well-known proof of the Pythagorean theorem. \nNeither the year nor place of his birth have been established, nor the circumstances of his death, although he is known to have lived and worked in Alexandria for much of his life. In addition, no bust which can be verified to be his likeness is known (Tietze 1965, p. 8).
146596
A courtier named Ts'ai-Lun, from Lei-yang in China, was the inventor of paper (not papyrus) circa 105 A.D. Tell your friend I'm sorry he/she lost the bet.
16358
History\nAn odometer for measuring distance is described by Vitruvius around 27 and 23 BC. The actual invention may have been by Archimedes during the First Punic War. Hero of Alexandria describes a similar device in chapter 34 of his Dioptra. The device was also invented in ancient China by Zhang Heng (78 – 139).\n\nThe odometer of Vitruvius was based on chariot wheels of 4 feet (1.2 m) diameter turning 400 times in one Roman mile (about 1400 m). For each revolution a pin on the axle engaged a 400 tooth cogwheel thus turning it one complete revolution per mile. This engaged another gear with holes along the circumference, where pebbles (calculus) were located, that were to drop one by one into a box. The distance travelled would thus be given simply by counting the number of pebbles. Whether this instrument was ever built at the time is disputed. Leonardo da Vinci tried to build it according to the description but failed. In modern times, however, Andre Sleeswyk was able to make a working model using gears similar to the Antikythera mechanism as opposed to the traditional cogwheel.\n\nThe odometer as used in most modern systems, where separate gears control each digit, was invented by William Clayton with help from Orson Pratt. Clayton, a Mormon Pioneer, developed the odometer (dubbed the "roadometer") to keep track of wheel revolutions on the pioneer carts. The odometer had multiple gears, including one which turned every quarter-mile and one which turned every ten miles.
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The formula is credited to Heron of Alexandria in the 1st century, and a proof can be found in his book Metrica. It is now believed that Archimedes already knew the formula, and it is of course possible that it has been known long before.\n\nLet the sides of a triangle have lengths a,b and c. Introduce the semiperimeter p = (a + b + c)/2 and the area S. Then Heron's formula asserts that\n S2 = p(p - a)(p - b)(p - c)\n\nW.Dunham analyzes the original Heron's proof in his Journey through Genius.\n\nFor the right triangle with hypotenuse c, we have S = ab/2. We'll modify the right hand side of the formula by noting that\n p - a = (- a + b + c)/2, p - b = (a - b + c)/2, p - c = (a + b - c)/2\n\nIt takes a little algebra to show that\n \n(a + b + c)(- a + b + c)(a - b + c)(a + b - c)\n= 2a2b2 + 2a2c2 + 2b2c2 - (a4 + b4 + c4)\n\nFor the right triangle, this expression is equal to 16S2 = 4a2b2. So we have\n 4a2b2= 2a2b2 + 2a2c2 + 2b2c2 - (a4 + b4 + c4)\n\nTaking all terms to the left side and grouping them yields\n (a4 + 2a2b2 + b4) - 2a2c2 - 2b2c2 + c4 = 0\n\nWith a little more effort\n (a2 + b2)2 - 2c2(a2 + b2) + c4 = 0\n\nAnd finally\n [(a2 + b2) - c2]2 = 0\nRemark\n\nFor a quadrilateral with sides a, b, c and d inscribed in a circle there exists a generalization of Heron's formula discovered by Brahmagupta. In this case, the semiperimeter is defined as p = (a + b + c + d)/2. Then the following formula holds\n S2 = (p - a)(p - b)(p - c)(p - d)\n\nSince any triangle is inscribable in a circle, we may let one side, say d, shrink to 0. This leads to Heron's formula.\n\nFor more information you can go to www.wikipedia.com  \nhttp://mathworld.wolfram.com/HeronsFormula.html\nhttp://www.cut-the-knot.org/pythagoras/herons.shtml\n\nI hope this helps! =-)
1060471
Martin Luther. \n\nNail those theses, baby.
661844
Do you mean the AUTHOR?\n\nAlgebra was created by the Egyptians, Balbylonians, and Greeks.
42250
what do you mean by angle ruler? protractor, or those triangle shaped ones? if u mean protractor, then you have to line up the point to the hole at the bottom middle hole. supposed to be one straight line that goes right or left. if it goes left, i think that you read the top row. if it goes right, the bottom row. hope that helps :)!
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This page gives a very nice table listing who, when, how, how accurately the speed of light has been measured including the first time when Olaus Roemer did it in a really neat way 330 years ago!\n\nhttp://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/measure_c.html
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As far as I know, it was invented by Martin Luther during the 1500's.  When he posted his Thesis against the Catholic Church, he used it to get the Word of God into the hands of the common people.