Since time immemorial, trigonometry has been used extensively to compute heights and distances of bodies, small and large. For instance, applications of trigonometry have been common in the field of astronomy to compute distances between celestial objects. Watch the embedded video to get the understand the basics of heights and distances. Subsequently, attempt the NCERT extra questions in this topic.
The angle of elevation of the top of a building from ground level is 30o. If the line of sight from the point of observation to the top of the building is 20 m long, what is the height of the building? How far from the base of the building is the point of observation?
A plumber uses a ladder to climb a wall that is 22 feet tall to fix a leak in the pipe at the top of the wall. He wants the ladder to reach a height that is 4.7 ft below the top of the wall, so that he can stand on the top rung and complete the task. If the ladder makes an angle of 60o with the ground, what is the length of the ladder and how far from the wall should he place the foot of the ladder? Take √3 = 1.73