A boy standing on the ground 25 feet from the base of a building looks up at the top of a building. The angle of elevation is 72°. Disregarding the boy’s height, how tall is the building? Round your answer to the nearest tenth of a foot.

Question

anonymous · Answer

7.55590

anonymous · Answer

r u sure

anonymous · Answer

$$25\tan(72)$$ whatever that is. it is not 7.5 though.  not a reasonable height for a building

anonymous · Answer

$$25 \text{Tan}[\pi  72/180]=25 \sqrt{5+2 \sqrt{5}}=76.9  $$

anonymous · Answer

that is one way to do it.  another is to whip out a calculator, make sure it is in degree mode, and compute

anonymous · Answer

I thank you your comment.  Have been converting degrees to radians in Mathematica until now.  Was unaware that there was a degree version of the argument.
$$\text{Tan}[72{}^{\circ}] $$computes just like the radian version of the argument.  The handheld calculator is probably the fastest in any case; three key strokes, 7,2,Tan.

 Just bought a fresh set of batteries for my HP 50g.  I may have missed out on some medals in the past.