Not sure if you're into trigonometry yet, but a good problem would be figuring out glide slope angle.
Draw a right triangle like this:
_____________ A
_____________/|
___________ /_|
_________/ ___ |
_______/ _____ |
____ / ________|
___/ |
B/____________| C
Point A is your airplane.
Point B is your touchdown spot at the airport.
Segment AC is your altitude. (suppose 1,000 ft)
Segment BC is your distance from the airport. (suppose 5 miles)
Now, you want to figure out at what angle you must descend to make your touchdown spot. (angle A). Using trig,
Tangent of angle A =Opposite over Adjacent legs
Opposite leg is BC (2 miles, which is 26,400 ft).
Adjacent leg is AC (1,000 ft)
So, if you're still reading this,
Tangent of CAB = 26,400/1000 = 26.4
Angle A = ~84.5 degrees.
Now, since Angle A is in the inside of the triangle, subtract the 84.5 degrees from 90 degrees to get the descent angle, which equals 5.5 degrees.
Therefore, you'll need to fly your descent at 5.5 degrees to make your touchdown point.
Hope that helps.
Since CAB is the inside angle of the triangle, subract this number from