- Construct a circle with a radius of 2 – 4 inches
- Fold the circle into quarters and cut along the folds
- Cut one of the quarters into eighths, two equal parts
- Glue the pieces onto a piece of paper and draw the rectangle
- The rectangle, ABCD has approximately the same area as the circle.
- Calculate the area of rectangle ABCD
- Construct another circle congruent to your first circle
- Fold the circle into eighths, or eight equal sectors
- Fit the circle pieces into a rectangle
- Calculate the approximate are by determining the area of the rectangle.
- Repeat the steps for a congruent circle cut into 16 sectors
- AB is approximately half of the circumference, 2πr, why? This means AB = πr
- Why does BC = r?
- The area of rectangle ABCD is

Area ABCD = AB x BC = πr x r = πr²