If you graph the points and connect them, you'll see the triangle they're asking about. Yhe base of the triangle is 9 and the height is 8. The area of a triangle is half of the base times the height. So multiply 8 by 9 and you get 72. This is twice the area. So divide it by 2 and you get 36, which is the area of the triangle. So the answer is A.