What is the diameter of this circle if the circumference is 30 pi inches? A circle. C = 30 pi in. 15 in. 30 in. 45 in. 60 in.

30 inches

Step-by-step explanation:

The circumference of a circle can be found using:

c=πd

The circumference is 30π inches. Substitute 30π in for c.

30π=πd

The question asks for the diameter. We have to solve for d. π and d are being multiplied. To reverse this, divide both sides by π, because division is the opposite of multiplication.

30π/π=πd/π

The πs on the right and on the left will cancel out.

30π/π=d

30=d

The diameter is 30 inches

b. 30 inches