Suppose you are standing 18 feet away from a tree, and that the angle of elevation from the ground where you are standing to the top of the tree is 60°. How tall is the tree?

Give your answer in exact radical form.

Now suppose you move away from the tree so that the angle of elevation from the ground where you are standing to the top of the tree is 30°. How far did you move?

Give your answer in exact form.