angle elevation of highest point of a building from points s and t are 60 and 30 respective. T is vertically above s and st 10 m calculate height above s, solution
Draw the diagram. It should be clear that
if the distance of ST to the building is x, and
the height of the building is h, then
(h-10)/x = tan30°
h/x = tan60°
So, eliminating x,
(h-10)/tan30° = h/tan60°
Now just solve for h