The figure shows three consecutive squares of sides 5, 4 and 3, respectively.
Find the area of the black region.
+36916 The total area of the 5 inch square would be 5 x 5= 25 units^2
a 4 x5 rectangle would be 20
a 3x5 rectangle would be 15 total 60
1/2 of this (due to the diagonal would be 30
Subtract the white rectangular areas above the 4 and 3 inch squares
30 - 4x1 - 3 x2 = 30 - 10 = 20 sq units
+36916 The total area of the 5 inch square would be 5 x 5= 25 units^2
a 4 x5 rectangle would be 20
a 3x5 rectangle would be 15 total 60
1/2 of this (due to the diagonal would be 30
Subtract the white rectangular areas above the 4 and 3 inch squares
30 - 4x1 - 3 x2 = 30 - 10 = 20 sq units
