Express the area a of a right triangle as a function of the height h if the height of the triangle is twice its base

Let ABC a right triangle with ∠ A= 90° and let AH = h, the height of Δ ABC.

 Area of Δ ABC = (base x height)/2 .
Area of Δ ABC = (BC x h)/2 . But h = 2.BC, then plugin the value of h
Area of Δ ABC = (BC x 2.BC)/2 .
Area of Δ ABC = (2.BC²)/2 .
Area of Δ ABC = (BC)²

See diagram.we use washers to get the area and we will be integrating with respect to xouter radius is the  distance between y = e^x and y = -1    inner radius of washer is the distance between y = 1 and y = -1    the area of one cross-section of a washer is    solid lies between x = 0 and x = 2. the volume is    if you need this expanded, then    the question doesn't say to evaluate, so we're done.   

Post the graph so people can answer