Page 282 #4.

Find the angle of elevation from a bench to the top of an 80 m high building if the bench is 105m from the foot of the building.

The correct answer is 37 degrees and 18

However, this is how I did it. I need to find the angle of elevation marked as "?" I did it with tan?=105/80 = 52.70 degrees.

Note: The graph I attached was how I thought the graph should look like based on the question. It may be wrong.
Thanks

Any help would be appreciated!

2. Originally Posted by fabxx
Page 282 #4.

Find the angle of elevation from a bench to the top of an 80 m high building if the bench is 105m from the foot of the building.

The correct answer is 37 degrees and 18

However, this is how I did it. I need to find the angle of elevation marked as "?" I did it with tan?=105/80 = 52.70 degrees.

Note: The graph I attached was how I thought the graph should look like based on the question. It may be wrong.
Thanks

Any help would be appreciated!
1. It is not a graph, it's a diagram.

2. The ? is in the wrong place. It should be on the INSIDE of the triangle.

3. $\displaystyle \tan{?} = \frac{\textrm{Opposite}}{\textrm{Adjacent}}$.

The Opposite side is the HEIGHT (80m) and the Adjacent side is the LENGTH (105m).

So it should be

$\displaystyle \tan{?} = \frac{80}{105}$

$\displaystyle ? = \tan^{-1}{\left(\frac{80}{105}\right)}$.