Expert: Sherman D. - 6/5/2005

Question
16. Lenght- The sun is 20deg above the horizon. Find the lenght of a shadow cast by a building that is 600 feet tall.

18. Height-- The lenght of a shadow of a tree is 125 feet when the angle of elevatin of the sun is 33deg. Approximate the height h of the tree

20. height- You are standing 100 feet from the base of a platform from which people are bungee jumping. The angle of elevation from your position to the top of the platfor from which they jump is 51deg. From what height are the people jumping.

22. An amatuer radio operator erects a 75 foot vertical tower for an antenn. Find the angle of elevation to the top of the twoer at a point on level ground 50 feet from its base.  

Answer
16.)
Since the Sun is 20° above the horizon, if i am correct thats as if you were looking up at the sun at a 20°.
Tan(20) = 600/x
x = 600/(tan(20))
x = 1648.49 feet

That was what i got
It might be
Tan(70) = 600/x
x = 218.38

But i am not 100% sure.

-----------------------------------------------------------

18.)
Tan(33) = x/125
x = 125 * tan(33)
x = 81.18 feet

The other possible answer is
Tan(57) = x/125
x = 125 * tan(57)
x = 192.48 feet

20 and 22 as far as i know of are correct, as for 16 and 18, i'm not certain.

-----------------------------------------------------------

20.)
Tan(51) = x/100
x = 100 * tan(51)
x = 123.49 feet

-----------------------------------------------------------

22.)
Tan(x) = 75/50
x = arctan(3/2)
x = 56.31°