Try it on paper first. A hint, the key idea and the worked solution are here when you need them.
A pole stands on top of a building m tall. From a point on the ground, the angle of elevation of the bottom of the pole is and of its top is . Find the distance of the point from the building and the length of the pole.
When one object stands on another, both lines of sight end on one vertical line, so the two triangles share the base . The length of the upper object is a difference of two heights, . An angle of depression equals the angle of elevation seen from the other end.
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. The distance. m.
Step 2. The height of the top. m.
Step 3. The pole. m.
Answer: the point is m from the building, and the pole is m long.
Log in to join the discussion.
Loading…