Step 1:
Divide the figure into parallelogram, trapezium and a rectangle.
Step 2:
Find the area of each figure
Area of parallelogram A

Area of rectangle B with dimension 18 in by 4 in

Find the area of trapezium C

Final answer
The area of the figure is the sum of the area of the trapezium, parallelogram and rectangle.
= 6 + 72 + 12
= 90