Circle Area: Slice the Circle Like a Pizza

Coming soon

The video is in production. Follow along on GitHub to hear when it is out.

The idea

Cut a circle into many thin wedges and fit them together top-to-tail, and the finer the cut, the closer it gets to a rectangle: its height is the radius r and its length is half the circumference, pi r, so the area is pi r squared.

A common mix-up

A circle is curved, so it can't be worked out like a rectangle; and cutting it into sixty-four pieces turns it into an actual rectangle.

Where it stops working

With only four pieces the shape is bumpy and nothing like a rectangle; however many pieces you cut, the edges still curve a little. It only gets closer and closer to a rectangle.

School year

China 6