Answer - 225
Area of parallelogram is given by formula = A = height * base
As per the question,
Base of parallelogram-shaped area in the backyard = b = 12 feet = 12*12 = 144 inches ( 1 feet = 12 inches)
Height of parallelogram-shaped area in the backyard = h = 9 feet = 9*12 = 108 inches ( 1 feet = 12 inches)
Area of parallelogram-shaped area in the backyard = A = 108 * 144 = 11232 square inches
area of 1 concrete patio stones = 50 square inches
the minimum number of stones that Deloris should buy to cover the parallelogram-shaped area in her backyard
=area of 1 concrete patio stone ÷ Area of parallelogram-shaped area in the backyard
= 11232 ÷ 50 = 224.64
the minimum number of stones that Deloris should buy to cover the parallelogram-shaped area in her backyard is 225.