Does anyone know where the circle was created, how it was created, who contributed to the construction of the circle, examples of circles today, and any interesting facts about the circle and its properties?
2007-11-18 09:41:12 · 8 answers · asked by mmholdford 2 in Science & Mathematics ➔ Mathematics
x^2 + y^2 = 1
That is the implicit way of defining a circle.
You can also parametrize it and change it to polar form.
x = rcosӨ, y = rsinӨ, r^2 = x^2 + y^2
In this case, r^2 = x^2 + y^2 = 1, r = 1.
cos^2Ө + sin^2Ө = 1.
2007-11-18 09:49:58 · answer #1 · answered by Axis Flip 3 · 0⤊ 0⤋
All access points for underground utilities - including but not limited to electric, telephone and especially sewers - use circles for the access point, because a circle is the only shape in which it is impossible for the lid to fall into the hole.
The strongest form of structural support is the half-circle or 'arch'. This could be why the construction of buildings is called 'architecture'. There are structures that were new when Julius Cesar was Emperor that are still in existence today, still capable of supporting weight because they were built as arches, as 1/2 of a circle.
Many 19th century bridges - especially railroad bridges - built of stone and using arches as the primary method for load bearing, are still in use, some more than 150 years after they were first constructed.
The circle is so old that it probably goes back to the days when we were busy building pyramids or even earlier.
2007-11-18 09:51:56 · answer #2 · answered by Paul R 7 · 0⤊ 0⤋
One property is that if you take the circumference of any circle and divide it by the diameter of that same circle.... You get "pi". Always.
Also, for a given perimeter, the circle is the shape that has the highest area for a 2-d figure.
I don't know who invented it. Euclid worked with it alot in "Euclid's Elements" a geometry compendum.
2007-11-18 09:44:31 · answer #3 · answered by Jeƒƒ Lebowski 6 · 0⤊ 0⤋
People have noticed circles ever since they gazed up at the round moon at night and then turned and stared into the pupils of their lovers' eyes.
2007-11-18 09:47:45 · answer #4 · answered by Michael M 7 · 1⤊ 0⤋
All about circles on this link
2007-11-18 09:45:21 · answer #5 · answered by Paul Goldsworthy 3 · 0⤊ 1⤋
http://en.wikipedia.org/wiki/Circle
2007-11-18 09:44:50 · answer #6 · answered by xxfoundthewayxx 2 · 0⤊ 1⤋
example wheel
2007-11-18 09:44:21 · answer #7 · answered by shiny11100 2 · 0⤊ 1⤋
its round??
2007-11-18 09:45:13 · answer #8 · answered by canadian 2 · 0⤊ 1⤋