I need help on this. How do you find the area of this shape?

To find the area of this shape you must first find the area of the rectangle 8 x 13 = 104. Once you find the area of the rectangle you must then find the area of the triangle which is base x height divided by 2. So to find the base of the triangle you must add the 4s on the bottom and subtract it by 13. So 13-8=5 so the base of the triangle is 5, the height is 6 and 5x6 is 30. You then divide it by 2 so you get 15. Now you take the area of the rectangle,104 and subtract it by the area of the triangle, 15. The answer is 89. I hope this helps.

Answer is either b or c