Question

1. adolfo wants to find the area of a circle with a diameter of 18 cm. which expressions can he use to find the area of the circle in square centimeters? choose all the correct answers. a) 2 9 π b) 18 π c) 3 3 π d) 18² π e) 9² * π

Explanation:

Step1: Find the radius

The radius $r$ of a circle is half of the diameter $d$. Given $d = 18$ cm, so $r=\frac{d}{2}=\frac{18}{2}=9$ cm.

Step2: Recall the area formula

The area formula of a circle is $A=\pi r^{2}$. Substituting $r = 9$ cm into the formula, we get $A=\pi\times9^{2}=9^{2}\cdot\pi$.

Answer:

E. $9^{2}\cdot\pi$