Answer:
I would say about B. 31 cm
Step-by-step explanation:
if you cut the shape into a triangle and a parallelogram, then you can easily guess that the other side of the square is about 4, and 4 x 4 is 16.. then you will multiply 8 by 4 and get 32 and then divide that by 2 and get 16 again, when you add both 16's together, you get 32, but 31 is closest
