## The Lesson

The diameter of a circle is found from the circumference of a circle using the formula:In this formula,

**C**is the circumference of the circle. The image below shows what we mean by finding the diameter from the circumference:

## How to Find the Diameter from the Circumference

Finding the diameter from the circumference is easy.## Question

What is the diameter of the circle, with circumference 30 cm, below?## Step-by-Step:

# 1

# 2

Substitute the circumference into the formula. In our example, C = 30.

Diameter =

^{30}⁄_{π}Diameter = 30 ÷ π Diameter = 30 ÷ 3.14 Diameter = 9.6 cm