The two guys story problem.
Two surveyors are walking along a flat dusty desert road after a long day claim staking when they see a strange object hovering motionless in the sky. Despite their shock, the older surveyor tells the younger surveyor to run down the road and when he shouts "now", to take a bearing and inclination to the object using his compass. (Or, if he doesn't have a compass, to put a stick into the ground that points to the center of the object.)
They only have time to take a quick measurement when the object zooms off. Afterwards, they take one measurement with their long tape measure.
Distance between observer A and observer B is 100 feet; they are on an east-west road, and observer B is to the east of Observer A.
Observer A recorded that the object was at a bearing of 030 degrees (N30E) and had an inclination of 82 degrees (up from horizontal).
Observer B recorded that the object was at a bearing of 315 degrees (N45W) and had an inclination of 80 degrees (up from horizontal).
Assuming that the measurements were taken at ground level (not eye level), how high above the ground was the object?
If the object was big enough, and stationary for enough time to take the measurements, two guys observing could also determine the size of the object by taking sight data on the edges of the object.
If they were fast enough, and took the measurements every few seconds, they could determine its speed.