Chapter 12.5, Problem 36S

To determine

The area of the following figure:

  

Answer to Problem 36S

The area of the given figure is $31.80f{t}^2$ .

Explanation of Solution

Given:

  

  $d=9ft$

Concept Used:

The area of semi-circleis given by the following expression:

  $A=\frac{\pi r^2}{2}$

Where,

Radius of semi-circle: $r$

Calculation:

The area of semi-circle is given by:

  $A=\frac{\pi r^2}{2}$

Put the given data:

  $\begin{array}{l}A=\frac{\pi r^2}{2}\\ A=\frac{\pi {\left(\raisebox{1ex}{$d$}\!\left/ \!\raisebox{-1ex}{$2$}\right.\right)}^2}{2}\\ A=\frac{\pi {\left(\raisebox{1ex}{$9$}\!\left/ \!\raisebox{-1ex}{$2$}\right.\right)}^2}{2}\\ A=31.80f{t}^2\end{array}$

Conclusion:

Hence, the area of semi-circleis $31.80f{t}^2$