Given
base = 10.6 yd
height = 6.4 yd - 1.4 yd = 5 yd
Solve for the area of the parallelogram first
Now that we have solved for the area, divide by 4 square yards, to determine the number of cans of sealant needed.
The result is 13.25 cans, therefore the city will be needing 14 cans in total for the treatment.