Question

Ruby wants to estimate the height of a streetlamp post on her block. She stands a certain

distance from streetlamp post and measures the angle of elevation to the top of the post (from

the ground) to be 71°. She walks 12 feet away from the lamp post. She then measures the angle

of elevation to the top of the post again, and this time finds it to be 46°. Estimate the height of

the street lamp post.

Answer 1

Answer: The height of street would be 3.26 feet.

Explanation:

Since we have given that

Angle of elevation = 71°

Distance traveled = 12 feet

Angle of elevation becomes 46°.

So, the height of the street lamp post would be

`h=(d)/(\cot 46^\circ-\cot 71^\circ)\\\\h=(12)/(0.965-0.344)\\\\h=(12)/(0.620)\\\\h=3.26\ feet`

Hence, the height of street would be 3.26 feet.