# Circles Mixed Exercises

Area and circumference both relate to the radius and diameter of a circle. Once you know one, you can find all of the others -- It just takes a little math!

### Practice Problems

##### Problem 1

Circumference = Π×diameter = 10 Π

radius = diameter ÷ 2 = 10 ÷ 2 = 5

Area = Π(radius)² = Π(5)² = 25Π