Question

point a is the center of the circle, and the length of ed is 18 centimeters.
a. what is the radius of this circle?
b. what is the circumference of this circle?

Explanation:

a. Step1: Find the radius

The diameter \(d = 18\) cm. The radius \(r=\frac{d}{2}\).
\(r=\frac{18}{2}=9\) cm.

b. Step1: Recall the circumference formula

The formula for the circumference of a circle is \(C = 2\pi r\) or \(C=\pi d\). We know \(d = 18\) cm.

Step2: Calculate the circumference

Using \(C=\pi d\), and taking \(\pi\approx3.14\).
\(C = 3.14\times18=56.52\) cm.

Answer:

a. \(9\) cm
b. \(56.52\) cm