Question

find the area and the circumference of a circle with diameter 9 ft. use the value 3.14 for π, and do not round your answers. be sure to include the correct units in your answers. area: circumference:

Explanation:

Step 1: Find the radius.

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

Step 2: Calculate the area.

The formula for the area $A$ of a circle is $A=\pi r^{2}$. Substitute $r = \frac{9}{2}$ ft and $\pi=3.14$. Then $A = 3.14\times(\frac{9}{2})^{2}=3.14\times\frac{81}{4}=63.585$ ft².

Step 3: Calculate the circumference.

The formula for the circumference $C$ of a circle is $C = 2\pi r$ or $C=\pi d$. Using $d = 9$ ft and $\pi = 3.14$, we get $C=3.14\times9 = 28.26$ ft.

Answer:

Area: $63.585$ ft²
Circumference: $28.26$ ft