Question

if a person is 6 feet tall and casts a 9 foot shadow, how tall would the shadow of a 100 foot tall tree be?

Answer 1

6 / 9 = 100 / x Multiply both sides with x

6 x / 9 = 100 Multiply both sides with 9

6 x = 9 * 100

6 x = 900 Divide both sides with 6ž

x = 900 / 6

x = 150 ft


OR

9 / 6 = 1.5

x / 100 = 1.5 Multiply both sides with 100

x = 1.5 * 100

x = 150 ft

Answer 2

or using proportions and cross multiply:
6:9
100:?
? = 100*9/6=150

Answer 3

A tree and a building stand side by side. The 5-foot tall tree casts a shadow of 12 feet. If the building is 80 feet tall, how long is its shadow?