Question

10 a circular coaster has a diameter of 5 inches. what is its area? write your answer using π. show your work.

Explanation:

Step1: Find the radius

The radius $r$ of a circle is half of the diameter $d$. Given $d = 5$ inches, so $r=\frac{d}{2}=\frac{5}{2}$ inches.

Step2: Use the area formula

The area formula of a circle is $A=\pi r^{2}$. Substitute $r = \frac{5}{2}$ into the formula: $A=\pi\times(\frac{5}{2})^{2}=\pi\times\frac{25}{4}=\frac{25\pi}{4}$ square - inches.

Answer:

$\frac{25\pi}{4}$ square inches