I'm having trouble figuring out what to do on these two questions.

1. A hot-air balloon is floating above a straight road. To calculate their height above the ground, the balloonists simultaneously measure the angle of depression to two consecutive mileposts on the road on the same side of the balloon. The angles of depression are found to be 21 degrees and 23 degrees.

How high (in feet) is the ballon?

I don't under stand how to figure this one out without the distances of the base.

2.For

find the values of the trigonometric functions based on the given one.

Note: The answer must be given as a fraction. NO DECIMALS.

If

then

=