Question

if a circle has a diameter of 8 cm, what is its area?
a. 25.12 cm²
b. 50.24 cm²
c. 16 cm²
d. 201 cm²

Explanation:

Step1: Find the radius

The radius \(r\) of a circle is half of the diameter \(d\). Given \(d = 8\) cm, so \(r=\frac{d}{2}=\frac{8}{2}=4\) cm.

Step2: Calculate the area

The formula for the area \(A\) of a circle is \(A=\pi r^{2}\). Using \(\pi = 3.14\) and \(r = 4\) cm, we have \(A=3.14\times4^{2}=3.14\times16 = 50.24\) \(cm^{2}\).

Answer:

B. \(50.24\ cm^{2}\)