https://en.wikipedia.org/wiki/Area_of_a_circle

Modern mathematics can obtain the area using the methods of ... geometry to show that the area inside a circle is equal to that of a right ...

http://www.ams.org/publicoutreach/feature-column/fc-2012-02

The area of any circle is equal to a right-angled triangle in which one of the sides about the right angle is equal to the radius, and the other to the circumference, ...

http://mathforum.org/library/drmath/view/70604.html

Mar 20, 2007 ... Do we know who figured out that pi*r^2 gives the area of a circle?

http://jwilson.coe.uga.edu/EMT668/EMAT6680.F99/Kim/emat6690/instructional%20unit/circle/Circle/Circle.htm

History. The study of the circle goes back beyond the recorded history. ... papyrus , gives a rule for determining the area of a circle that corresponds to 256/81 or ...

https://www.youtube.com/watch?v=YokKp3pwVFc

Mar 18, 2011 ... Read a more complete explanation here: http://pythagoreanmath.com/complete- explanation-for-area-of-a-circle-formula/ πr(squared) gives you ...

https://www.khanacademy.org/math/8th-grade-foundations-engageny/8th-m5-engage-ny-foundations/8th-m5-tb-foundations/a/area-of-a-circle

Instead, let's start by estimating the area of the circle first. Since calculating the area of a square is easy, we can estimate the area of a circle by comparing it to ...

https://www.khanacademy.org/math/basic-geo/basic-geo-area-and-perimeter/area-circumference-circle/a/radius-diameter-circumference

A circle is a shape where distance from the center to the edge of the circle is always the same: Created ..... Finding circumference of a circle when given the area.

https://www.basic-mathematics.com/proof-of-the-area-of-a-circle.html

Proof is usually done with calculus. However, find here a nifty proof of the area of a circle using only basic math concepts.

https://www.mathopenref.com/circleareaderive.html

This page describes how to derive the forumula for the area of a circle, by using ther fact that in a regular polygon, as you increase the numbr of sides, ...

https://www.khanacademy.org/math/basic-geo/basic-geo-area-and-perimeter/area-circumference-circle/v/area-of-a-circle

The area of a circle is pi times the radius squared (A = π r²). Learn how to use this formula to find the area of a circle when given the diameter. Created by Sal ...