The area of a trapezoid is:
Where h is the height and and are the upper and lower bases.
You might need to change your perspective. Remember that the bases have to be parallel sides!
Now for the next question....you have to know that the integral is the area under the curve (or line). Here, you're trying to find the area under the curve between 2 and 5.
As for question (c): I guess you have to integrate