SOLUTION
Let us start by forming the composite figure into two groups.
From the figure above, section A of the composite figure is a triangle.
The formula to calculate the area(A1) of a triangle is
[tex]A_1=\frac{1}{2}bh[/tex]
Given:
[tex]\begin{gathered} b=\text{base}=3mm+6mm+3mm=12mm \\ h=\text{height}=25mm-19mm=6mm \end{gathered}[/tex]
Hence,
[tex]A_1=\frac{1}{2}\times12\times6=36mm^2[/tex]
Section B of the composite figure is a rectangle.
The formula to calculate the area(A2) of a rectangle is
[tex]A_2=wl[/tex]
Given:
[tex]\begin{gathered} w=6mm \\ l=19mm \end{gathered}[/tex]
Therefore,
[tex]A_2=6\times19=114mm^2[/tex]
Hence, the area of the composite figure(A) will be
[tex]\begin{gathered} A=A_1+A_2=36+114=150 \\ \therefore A=150mm^2 \end{gathered}[/tex]
Therefore the area of the composite is
[tex]150mm^2[/tex]
