you can add up all the sides, so for the base, you'll get 8x3/2 but since you have 2 same base, you can just cancel out the /2. so the answer is 24. then add up the other sides, we have 2 9x5 rectangles, and a 8x9 side at the bottom. so just add 24 + 90 + 72, so the final answer should be 186 cm2