ok so lets start of with the fact that the whole thing is 21 units.
So we do 21-9=12 so then we now know that the rectangle is 12 so then we do 12*8 units which is= 96 . Now the triangles. so the first one we know that its 8*3 and times it by 1/2 because two triangles is equal to a rectangle so the first triangle is 12 and now the second. its 9-3= 6 then its 6*8*1/2 which is equal to 24 so now the final answer is
96+12+24 which is equal to 132 so i'm guessing it 132 square units