Say I'm at an unknown distance from a mountain, called point P, and I estimate the angle of elevation to the top of the mountain is 13.5 degrees. Then I move to point N, which is 100 meters closer to the mountain, and I estimate the angle of elevation to be 14.8 degrees. What is the height of the mountain?

2 answers

review the basic trig functions. You will see that if the height is h,

h cot13.5° - h cot 14.8° = 100
Tan13.5 = h/P, h = P*Tan13.5.
Tan14.8 = h/(P-100), h = (P-100)*Tan14.8.

P*Tan13.5 = (P-100)*Tan14.8,
P = (P-100)*1.10,
0.91P = P-100,
P = 1,111 Ft.

h = P*Tan13.5 = 1111*Tan13.5 = 266.8 Ft.