Hello, victorfk06!
A lighthouse keeper 120 feet above the water sees a boat
sailing in a straight line directly toward her.
As she watches, the angle of depression to the boat changes from 28° to 43°.
How far has the boat traveled during this time? Code:
A * - - - - - - - - - - -
| * 28°
| 62° *
| *
120 | *
| *
| *
| *
| *
* - - - -*- - - - - - - - - *
B y C x D
In right triangle .[1]
Code:
A * - - - - - -
|* 43°
| *
| *
120 |47°*
| *
| *
| *
| *
* - - - -*
B y C
In right triangle .[2]
Substitute [2] into [1]: .
. . Therefore, the boat traveled about 97 feet.