prove it.
show your work

On Jan 1, 8:53 pm, Mxsmanic wrote:
Tina writes:
You can be fairly sure he used someone else's equations for line of
sight. I'd bet a significant sum he could not derive them himself. He
and Euclid would not have gotten along.

It's just simple trig. In fact, it's just solving for different sides of a
right triangle, as should be obvious from the description I gave.