Question

If the circumference of a circle is 18pi centimeters, what us the diameter of the circumference of the circle?

C= pi
A 9 centimeters
B 18 centimeters
C 9 pi centimeters
D 18pi centimeters
please help

Answer 1

Hello there!

Now, the formula to find the circumference of a circle is C = 2
`\pi`r. Now, since the circumference is 18
`\pi`, all we have to do is to divide 18 by 2 to find the radius!

The radius of the circle is 9 cm, since 18/2 = 9. However, this is the radius. We need the diameter.

Multiply 9 by 2 to find the diameter. 9 · 2 = 18. So the answer is B. 18 centimeters.

Hope this helped!