Math Question?

Question

Given a circle transcribed in a triangle, prove that area of triangle= sr, where 2s=periminter of triangle and r=raidus of circle, the triangle is equilat

Answer 1

Draw the figure with the circle inside. Draw three radii, one to each tangency point. Also draw a segment from the center to each vertex of the triangle. This makes 6 identical right triangles (radius is perpendicular to a tangent). Each has a leg of r and the other leg s/3, so each one's area is 1/2(r)(s/3) = rs/6, and there are 6 of them, so the total area is rs

Answer 2

Here's a picture if you need it:

http://mudandmuck.com/triangle.JPG

p.s., I think you mean "inscribed", don't you?

Answer 3

http://mathforum.org/dr.math/faq/formulas/faq.triangle.html#equilateral

Answer 4

Eh, how about editing this so that it makes sense....