-- The little block on top is 6-high by 5-wide = 30 square inches.
-- The dotted line across the middle is 5 inches long.
-- The long skinny block on the bottom is (10-6)=4-high by 12-wide = 48 inches² .
-- The height of the triangle at the end is (10-6) = 4 inches.
The base of the triangle is (15 - 7 - 5) = 3 inches.
The area of the triangle is (1/2)(base)(height) = 6 inches².
-- Sum of the the 3 sections = (20 + 48 + 6) = 74 square inches.