To answer this question, you should draw it out- see the attached picture for the example. All the side lengths are labeled. You can then use the area of a trapezoid formula to find the total area.
A=1/2 (b1 + b2)h
You can see the substitution for each value in the work shown in the picture.
A=1/2 (b1 + b2)h
You can see the substitution for each value in the work shown in the picture.