# Math Help - Angles of Elevation and Deppresion

1. ## Angles of Elevation and Deppresion

Can someone please solve this for me, and tell me how to solve it? Ive tried and tried but no good.

A person stands on one side of a street and looks up to the top of a building on the other side of the street. To do this, the persons line of sight must be elevated 65 degrees. From the opposite side of the street, to do the same thing the angle of elevation of the line of sight must be 70 degrees. If the buildings are 15metres different in height, how wide is the street?

cheers.

2. Originally Posted by SMC
Can someone please solve this for me, and tell me how to solve it? Ive tried and tried but no good.

A person stands on one side of a street and looks up to the top of a building on the other side of the street. To do this, the persons line of sight must be elevated 65 degrees. From the opposite side of the street, to do the same thing the angle of elevation of the line of sight must be 70 degrees. If the buildings are 15metres different in height, how wide is the street?

cheers.
let $h$ = height of the shorter building

$w$ = street width

$\tan(65) = \frac{h}{w}$

solve for $h$ ...

$
h = w\tan(65)
$

$\tan(70) = \frac{h+15}{w}$

sub in $w\tan(75)$ for $h$ in the above equation and solve for $w$