Answer: 
Step-by-step explanation:
The figure is attached (which is based on the description given)
Notice that you can divide it into two figures: a rectangle and a triangle.
The area of a rectangle can be found with this formula:

Where "l" is the length and "w" is the width.
In this case:

Therefore, the area of the rectangle is:

The area of a triangle can be calculated with the following formula:

Where "b" is the base and "h" is the height.
In this case, you can identify that:

Therefore, substituting values and evaluating, you get:

Finally, you must add the areas calculated above, in order to find the area of the wall. This is:
