The plate is a circle.
diameter = 8 inches
[tex]\begin{gathered} \text{area}=\pi r^2 \\ \text{where} \\ r=\text{radius}=\frac{8}{2}=4\text{ inches} \\ \text{area}=\pi\times4^2 \\ \text{area}=16\pi \\ \text{area}=\frac{22}{7}\times16 \\ \text{area}=\frac{352}{7}=50.2857142857 \\ \text{area}=50.30inches^2 \end{gathered}[/tex]