If a 36-foot tree casts a 28-foot shadow at the same time near by building casts a 70-foot shadow, how tall is the building?

Question

anonymous · Answer

hello radar!

radar · Answer

36/28  = x/70  set up a proportion.
28x=70X36

radar · Answer

Hey satellite73, whats happening?

anonymous · Answer

i got 90

anonymous · Answer

http://openstudy.com/groups/mathematics/updates/4df50eb20b8b370c28bc944e

radar · Answer

Hikari93, can you take it from there.  If not let me know.
One thing we can say, looking at the problem the building is taller than the shadow because the tree is taller than its shadow.

radar · Answer

I got 90 also.

anonymous · Answer

$$\theta =atan(36/28)=52.139$$$$70\times \tan \theta =90.046\approx 90$$