A flagstaff stands on top of a vertical tower. A man standing 60 m from the tower observes that the angles of elevation of the top and bottom of the flagstaff are 64∘ and 62∘ respectively. Find the length of the flagstaff.
Worked solution (try it first)
Here the distance, 60 m, is adjacent to the angle and the height is opposite, so each height is 60tanθ.
The top of the flagstaff is 60tan64∘ high and the bottom is 60tan62∘ high.
The flagstaff is the top minus the bottom: 60(tan64∘−tan62∘), option D.