Question

question
the diameter of a circle is 18 in. find its area in terms of π.
answer
attempt 1 out of 2
a = in²
submit answer
π

Explanation:

Step1: Find the radius

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

Step2: Use the area formula

The area formula of a circle is \( A=\pi r^{2}\). Substitute \( r = 9\) into the formula: \( A=\pi\times(9)^{2}\).

Step3: Calculate the result

\( A=\pi\times81 = 81\pi\)

Answer:

\(81\pi\)