1. ## Trig Revision

Hi

For the question:

An observer finds that the angle of elevation of the top of a tower from a pt A is 46 degrees. On walking 100 m closer to the ower, she finds that the angle of elevation becomes 66 degrees. Find the height of the tower to the nearest metre.

How exactly do I start this question??

Thanx

2. Originally Posted by xwrathbringerx
Hi

For the question:

An observer finds that the angle of elevation of the top of a tower from a pt A is 46 degrees. On walking 100 m closer to the ower, she finds that the angle of elevation becomes 66 degrees. Find the height of the tower to the nearest metre.

How exactly do I start this question??

Thanx
draw the situation to visualize, that would be a good start..
then, think of the ways on how you could be able to use these concepts: SOHCAHTOA, similar triangles..

3. I've already drawn it but I can't seem to be able to use any of the info to find out anything useful.

4. post what you have drawn (with the info, of course) in your next reply...

5. Originally Posted by xwrathbringerx
i have expected that you would label some important points.. anyways..
let $T$ be the point above and $O$ be the point on perpendicularity.. let $B$ be the point between $O$ and $A$

let $|OA| = x$, $|BA| = 100$ so that $|OB| = x-100$

using SOHCAHTOA
$|OT|=|OB|\tan(66^{\circ}) = |OA|\tan(46^{\circ})$
or
$|OT|=(x-100)\tan(66^{\circ}) = (x)\tan(46^{\circ})$

using the middle and the right side, solve for $x$, then substitute $x$ to solve for $|OT|$..