I FOUND YOUR FULL QUESTION IN OTHER FUENETES. PLEASE SEE ATTACHED IMAGE. For this case what you should do is find the area of the triangle which will be given by: A = (1/2) * (b) * (h) Where b: base h: height Substituting the values we have: A = (1/2) * (25 1/2) * (15) A = 191.25 feet ^ 2 Answer: she will need 191.25 feet ^ 2 to cover the back of the cabin