Even they are the same areas but they are not the same shape; the diagonal lines in both shapes are not straight lines. The slopes are 2/5 and 3/8 for dark green and red areas accordingly. 
5 i5 H! @' o, v5.39.217.77On the other hand, if you imagine to fill the missing part to make it as a rectangle; the missing area of the top shape is 33 blocks = (5 * 2 / 2 = 5) + (8 * 3 / 2 = 12) + (8 * 2 = 16) 8 K+ e6 g/ L1 H! |* B 
But for the missing areas of the bottom shape is 32 blocks = (5 * 2 / 2 = 5) + (8 * 3 / 2 = 12) + (5 * 3 = 15) |