You can find the area of the square, and both triangles. The square would be 9 × 9 = 81cm^2, and the two triangles would be 12 × 9 = 108. Normally you would divide that by 2, but there are two identical triangles so we can leave it how it is. 108 + 81 = 189cm^2, which is your answer. I hope this helps!