Answer:
17.5m
Explanation:
We solve using the formula
Height /Shadow
Height of flag staff = 7m
Shadow of flag staff = 8.2 m
Height of the building = x
Shadow of the building = 20.5
= 7/8.2 = x/20.5
Cross Multiply
8.2x = 7 × 20.5
x = 7 × 20.5/8.2
x = 143.5 / 8.2
x = 17.5m
The height of the building is 17.5 m