To obtain the area of the composite figure, the following steps are necessary:
Step 1: Recall the formulas for the area of a rectangle and a triangle (since they both make up the composite figure), as given below:

Step 2: Compute the areas of the rectangle and triangle using the formulas above

Step 3: Add the two areas together, as follows:

Thus:

Therefore, the area of the composite figure is 51 inches squared (option A)