Question

Write and solve a proportion to find the height of the building.

Answer 1

Write and solve an equation of ratios:

9 ft          22 ft

------- = -----------

h               99 ft

This is appropriate because h is greater than 9 ft.

cross-multiplying, we get 

9(99) ft^2 = 22*h*ft

Then h =40.5 ft (which is the height of the building)

Answer 2

Remark

Keep the objects on one side of the proportion and the shadows on the other side. The length of the shadows should be right across from the height of the of the object it represents.

Formula

$\dfrac{\text{Height of Building}}{\text{Height of Flagpole}}=\dfrac{\text{Length of Building Shadow}}{\text{Length of Flagpole Shadow}}$

Sub and Solve

Let the height of the building = x

x/99 = 9/22 Cross multiply.

22x = 9 * 99

22x = 891 Divide by 22

x = 891/22

x = 40.5

The height of the building is 40.5 feet <<<< Answer