Hello, tiar!

A flagpole is located at the edge of a sheer 50ft cliff at the bank of a river 40 feet wide.

An observer on the opposite side of the river measures an angle of 9 degrees between

her line of sight to the top of the flagpole and her line of sight to the top of the cliff.

Find the height of the flagpole. Code:

o A
* |
* |
* | h
* |
* o B
* * |
* 9° * |
* * | 50
* * θ |
P o - - - - - - - - - o C
40

The flagpole is

The cliff is

The observer is at

Let

In right triangle

In right triangle

. . Note that: . .

Substitute into [1]: .

Therefore: .