Year 9 Interactive Maths - Second Edition

Circumference of a Circle

The perimeter of a circle is called the circumference.  The circumference is the distance around the circle.

where r is the radius of the circle, and

Example 4

A circular swimming pool has a radius of 14 m.  Find the circumference of the pool.

Solution:

So, the circumference of the pool is 88 m.

Note:

Example 5

A circular flower-bed has a radius of 9 m.  Find the circumference of the flower-bed.

Solution:

So, the circumference of the flower-bed is 56.5487 m.

Key Terms

circumference