This document explains how two people proved that the formula for calculating the area of a circle (A=πr2) is valid. They started by cutting a circle into 24 equal pieces and arranging them into a rectangular shape. By measuring the length and width of this rectangle, they were able to show that the area calculated using l×w matched the area calculated using πr2. This demonstrated that πr2 accurately describes the area of a circle.

1. By Jari and Tom