The formula for the area of a circle is a little more difficult and requires methods of successively better approximations.
The usual definition of π is the ratio of the circumference of a circle to its diameter d, so that the circumference of a circle is πd, or 2πr, where r is the radius.
shows that a
circle can be cut and rearranged to closely resemble a
height r and base πr)
of area πr
By dividing the circle into more than eight
slices, the approximation obtained in this manner would be even
dividing the circle into more and more slices, the approximating
approximate the area of the circle arbitrarily closely. This gives
justification that the area of a circle really is
<-- Previous : Home : Next -->
Rectangle : Parallelogram : Triangle
1. : Triangle
2. : Trapezoid 1.
1. : Circle
Bettina Richmond and Tom Richmond.
Updated May 22, 2008.