By: Tim Lehman

Students can start to study area of circle
by first discussing ways to estimate their area. They can see
by inscribing regular polygons with more sides a better estimate
is given. From the previous lesson, students found the area of
various regular polygons. This can be used to find the estimates.
**Click here** for a GSP
Sketch.

Exact area of circles should be found as well.
Students need to understand circumference for this part of the
lesson (from **Lesson 3**). One
way to find the area of a circle involves slicing the circle into
small pieces. Then, rearrange them to look more like a rectangle,
a shape that has an area we know. **Click
here** for a GSP 3.0 sketch of this idea. A short clip on
the video *The Story of Pi* presents a great visualization
as well.