Area of a Circle

Today we saw how the area of a circle relates to the area of a parallelogram.

If we cut a circle and rearrange its parts to be rectangular, we can see that the height is equal to the radius of that circle






The length or base is equal to half the circumference (3.14 x r) of the circle.

Therefore, the area of a circle is 3.14 x r xr

Look at the site Math Goodies for a good refresher.

Tonight, complete Practice Worksheet 10-2.