We have a right triangle with a 41 degree angle and an adjacent of 150m, and we want the opposite, so since tangent is o/a, height is 150m * tan(41 degrees). Of course, if the distance is not ground horizontal displacement distance but diagonal point to point, like from a range finder, then the 150m is a hypotenuse, in which case o/h is sine: 150m * sin( 41 degrees ). We hope the range finder was pointed at the base of the tower! Any ground height variations between beneath the plane and the base of the tower would also mess this up! :D
