Subject & Study Guides: DIY Maths: Area of circles

AREA OF CIRCLES

In this module, you can study what the area of a circle is and how to find the area of a circle if you know its diameter or radius.

If a circle and a square have the same perimeter, their areas will be different.

Pi times r-squared means Pi x radius x radius. It does NOT mean Pi x radius x 2.

Try your hand at changing the area enclosed by a circle
This page on mathopenref.com lets you see how the area of the circle changes as you adjust its radius.
Read about how to find the area of a circle
This link from mathisfun.com shows how to use different formulae to find the area of a circle. Also, there's a special calculator you can use that's just for finding the area of a circle.
Quiz yourself on finding the area of circles
This quiz at aaastudy.com will help you check your understanding of the circle area calculation.