 |
| ||
| |||
|
| Math Central | Quandaries & Queries |
|
Question from joyce, a student: The angle of elevation of tower B from the top of tower A is 28 degrees and the angle of elevation of the top of tower A from the base is 46 degrees. Find the height of tower A if tower B is 120 m high? |
Hi Joyce.
I drew a diagram of the problem on the right.
We want AE.
We know DB = 120m, 
CBA = 28°, ADE = 46°.
First, note that AE = AB tan 46°. Also, AE = CD.
Now, note that BC = AC tan 28°. Also AC = AB.
Thus, DB = AB tan 46° + AB tan 28° = 120m.
Solve for AB. Use this to solve for AE in our earlier equation.
Hope this helps,
Stephen La Rocque.
| ||
| ||
| ||
 |
 |
|
Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.