Question

Match the circumference of a circle with its radius (in the left column).

• A. $6\pi$
• B. $8\pi$
• C. $10\pi$

Answer 1

The circumference of a circle is $2\pi r$, where $\pi$ is a constant and $r$ is the radius of the circle.

For $r=3$, we have:
Circumference $=2\times 3\pi$
Circumference $=6\pi$

For $r=4$, we have:
Circumference $=2\times 4\pi$
Circumference $=8\pi$

For $r=5$, we have:
Circumference $=2\times 5\pi$
Circumference $=10\pi$