Solution:
Given the figure below:
The area of the shaded region is expressed as
[tex]area\text{ of shaded region = area of semicircle - area of triangle}[/tex]
step 1: Evaluate the area of the semicircle.
The area of the semicircle is expressed as
[tex]\begin{gathered} area\text{ of semicircle=}\frac{1}{2}\times\pi r^2 \\ where\text{ r is the radius of the circle} \end{gathered}[/tex]
Thus, we have
[tex]\begin{gathered} area\text{ of semicircle = }\frac{1}{2}\times3.14\times4cm\times4cm \\ \Rightarrow area\text{ of semicircle =25.12 cm}^2 \end{gathered}[/tex]
step 2: Evaluate the area of the triangle.
The area of the triangle is expressed as
[tex]\begin{gathered} area\text{ of triangle =}\frac{1}{2}\times base\times height \\ thus,\text{ we have} \\ area\text{ of triangle =}\frac{1}{2}\times8cm\times4cm \\ =16\text{ cm}^2 \end{gathered}[/tex]
step 3: Evaluate the area of the shaded region.
Recall that
[tex]\begin{gathered} area\text{ of shaded reg}\imaginaryI\text{on = area of sem}\imaginaryI\text{c}\imaginaryI\text{rcle- area of tr}\imaginaryI\text{angle} \\ \end{gathered}[/tex]
Thus, we have
[tex]\begin{gathered} area\text{ of shaded region = \lparen25.12 -16\rparen cm}^2 \\ =9.12\text{ cm}^2 \end{gathered}[/tex]
Hence, the area of the shaded region is
[tex]9.12\text{ cm}^2[/tex]
