Practice Pi (π) in Math

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

The ratio of a circle's circumference to its diameter, approximately 3.14159\ldots

No matter how big or small the circle, circumference \div diameter always equals \pi.

Example 1

easy
A circle has a diameter of 10 cm. What is its circumference? Use \pi \approx 3.14.

Example 2

medium
A circle has a radius of 7 m. Find its area. Use \pi \approx 3.14.

Example 3

medium
A circular pool has a circumference of 31.4 m. Find its radius and area. Use \pi \approx 3.14.

Example 4

easy
A circle's circumference is C = 62.8 cm. What is its diameter? Use \pi \approx 3.14.

Example 5

hard
A wheel of radius 0.5 m rolls without slipping. How many full rotations does it make to travel 100 m? Use \pi \approx 3.14159.