Question

find the area of the circle with the following dimension. diameter = 18 cm the area is cm². (round to the nearest tenth as needed.)

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: Calculate the area.

The formula for the area $A$ of a circle is $A=\pi r^{2}$. Substitute $r = 9$ cm into the formula, we get $A=\pi\times9^{2}=81\pi$ $cm^{2}$.

Step3: Round the result.

Using $\pi\approx3.14159$, $A = 81\pi\approx81\times3.14159 = 254.46879$ $cm^{2}$. Rounding to the nearest tenth, $A\approx254.5$ $cm^{2}$.

Answer:

$254.5$