C /|\ / | \ / | \ / O \ / . . \ /x . .z\ /. w y .\ A-----------------B D
Two observers, A & B, are a distance D apart on flat ground and are both
looking at the same object C above them (just for the sake of argument,
let's say it's the point of maximum height of a water rocket.)
With the angles they measure,
they want to determine the height of C above the ground.
Assume that point O on the ground is directly below C
(AOC and BOC are right angles).
Find OC in terms of D and the necessary angles (I don't think all of the angles will be needed.)
Source: Original (personal necessity...) A good starting place for water rocketry is: www.h2orocket.com