Question

Circle O has a circumference of 36π cm. Circle O with radius r is shown. What is the length of the radius, r? 6 cm 18 cm 36 cm 72 cm

Answer 1

18 centimeters

Explanation:

The circumference of a circle can be found using the following formula.

`c=2\pi r`

We know the circumference is 36π cm, therefore we can substitute 36π in for c.

`36\pi= 2 \pi r`

We want to find r, the radius. Therefore, we must get r by itself. First, divide both sides of the equation by pi.

`36\pi / \pi = 2 \pi r / \pi\\\\36= 2 \pi r / \pi\\\\36=2r`

Next, divide both sides of the equation by 2.

`36=2r \\\\36/2=2r/2\\\\36/2=r\\\\18=r\\\\r=18 cm`

The radius of Circle O is 18 centimeters.

Answer 2

18 cm.

Explanation:

The circumference of a circle is found by calculating 2 * pi * r.

In this case, the circumference is 36 pi cm.

2 * pi * r = 36 * pi

2 * r = 36

r = 36 / 2

r = 18 cm.

Hope this helps!