# What is meant by this?

• October 15th 2010, 04:15 PM
What is meant by this?
I am having trouble understanding this problem.
It has to deal with either cosine or sine law.

The angle of depression of a fire noticed west of a fire tower is 6.2 degrees. The angle of depression of a pond, also west of the tower, is 13.5 degrees.
If the fire and pond are the same altitude, and the tower is 2.25 km from the pond on a direct line, how far is the fire from the pond?

So do I take the fire and pond are level together on the ground, on a horizontal plane from the angles noted above??

Not sure how to solve this, and do I have enough info??
• October 16th 2010, 01:28 AM
earboth
Quote:

I am having trouble understanding this problem.
It has to deal with either cosine or sine law.

The angle of depression of a fire noticed west of a fire tower is 6.2 degrees. The angle of depression of a pond, also west of the tower, is 13.5 degrees.
If the fire and pond are the same altitude, and the tower is 2.25 km from the pond on a direct line, how far is the fire from the pond?

So do I take the fire and pond are level together on the ground, on a horizontal plane from the angles noted above??

Not sure how to solve this, and do I have enough info??

1. Draw a rough sketch.

2. You are dealing with 2 right triangles with the height of the tower as the common leg.

3. Calculate the height of the tower (use the tan-function)

4. Calculate the distance fire-tower and then the distance I labeled "x".

5. For confirmation only: I've got $x \approx 2.722\ km$
• October 16th 2010, 11:48 AM