Think of it as a big rectangle with a triangle piece taken out of it so the area completely if nothing were chipped out would be 33x22 which are 726 the area of the triangle would be base x height / 2 the height would be 10 because 22-12 is 10 its base is 9 because 33-24. so 10 x 9 is 90 that / 2 is 45. 726 - 45 is 681. 681 is the answer.
