Then the second trapezoid is going to look like this. I guess you could say a trapezoid where one of the sides has length zero turns into a triangle. Then the third trapezoid is going to look like this. And then the fourth trapezoid is going to look like that. And then finally you have the fifth trapezoid. So let's calculate the area of each of these, and then we will have our approximation for the area under the curve. So let's do trapezoid, or I really should say triangle, this first shape, whatever you want to call it.