In the figure, there are two triangles and one square .
The area of square is
[tex]A_1=6\times6=36sq.\operatorname{mm}[/tex]
The area of triangle is
[tex]A_2=\frac{1}{2}\times8\times6=24sq.\operatorname{mm}[/tex]
The area of triangle is
[tex]A_3=\frac{1}{2}\times8\times6=24sq.\operatorname{mm}[/tex]
Thus the area of the figure is sum of area of square and area of two triangles.
[tex]A=36+24+24=84sq.mm[/tex]
