ANSWER
[tex] 400 \: {in}^{2} [/tex]
EXPLANATION
The figure is made up of a parallelogram and a right angle triangle.
The area of the parallelogram is
[tex] = base \times height[/tex]
The base of the parallelogram is 20 inches.
The height of the parallelogram is 16 inches.
The area of the parallelogram is
[tex] = 20 \times 16 \: i {n}^{2} [/tex]
[tex] =320 \: i {n}^{2} [/tex]
The area of the triangle is
[tex] = \frac{1}{2} \times base \times height[/tex]
The base of the parallelogram is also 20 inches because opposite sides of a parallelogram are equal in length.
This implies that the area of the triangle is
[tex] = \frac{1}{2} \times 20 \times 8 \: {in}^{2} [/tex]
[tex] = 10 \times 8 \: {in}^{2} [/tex]
[tex] = 80 {in}^{2} [/tex]
We add the two areas to get the area of the figure.
[tex] = 320 + 80 \: {in}^{2} [/tex]
[tex] = 400 \: {in}^{2} [/tex]
