Jill is standing at the base of her apartment building. She measures the angle of elevation to the top of a nearby tower to be 40º. Then Jill goes to the roof of her apartment building, directly above her previous position, and measures the angle of elevation to the top of the same tower to be 30°.
If the height of the tower is 100 meters the height of jills apartment is ____ meters.

Question

Jill is standing at the base of her apartment building. She measures the angle of elevation to the top of a nearby tower to be 40º. Then Jill goes to the roof of her apartment building, directly above her previous position, and measures the angle of elevation to the top of the same tower to be 30°.
If the height of the tower is 100 meters the height of jills apartment is ____ meters.

campbell_st · Answer

start by drawing a a dagram 

|dw:1423084222490:dw|

find y by using the sign ratio. 

then you can use the law of sine or sine rule to find the height of Jill's building
but to fue the law of sines, you need to find the 2 given angles. 

hope  it helps