Question

a dime has a diameter of 17.91 millimeters. What is the area of the face of the dime? use 3.14 for π. Round to the nearest hundredth if necessary

Answer 1

The area of a circle is:

$A=\pi\cdot r^2$

As you have the diameter, use it to find the radius: the radius of a circle is equal to the half of the diameter:

$\begin{gathered} r=\frac{d}{2} \\ \\ r=\frac{17.91\operatorname{mm}}{2}=8.955\operatorname{mm} \end{gathered}$Then, the area is: 251.80 millimeters$\begin{gathered} A=(3.14)(8.955mm)^2 \\ A=251.80\operatorname{mm} \end{gathered}$