The angle of elevation of a building from a measuring instrument placed on the ground is 30o. If the building is 40m high, how far is the instrument from the foot of the building?
- \(\frac{20}{√3}\)m
- \(\frac{40}{√3}\)m
- 20√3m
-
40√3m
The correct answer is: D
Explanation
\(\frac{40}{x}\) = tan 30o
x = \(\frac{40}{tan 30}\)
= \(\frac{40}{1\sqrt{3}}\)
= 40√3m