Question

A ranger spots a fire from a 73-foot tower in Yellowstone National Park. She measures the angle of depression to be 1°20'. How far is the fire from the tower?

Answer 1

`3136.4` ft

Explanation:

Let the distance between the fire and the bottom of the tower be `x`,

`1^@20'=(80/60)^@=(4/3)^@`

`tan (4/3)^@=73/x`
`=> x=73/tan(4/3)=3136.4` ft. (1dp)