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?
-
A.
(frac{20}{√3})m -
B.
(frac{40}{√3})m -
C.
20√3m -
D.
40√3m
Correct Answer: Option D
Explanation
(frac{40}{x}) = tan 30o
x = (frac{40}{tan 36})
= (frac{40}{1sqrt{3}})
= 40√3m