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
Verified Correct Answer: D.
Step-by-Step Mathematical Solution
\(\frac{40}{x}\) = tan 30o
x = \(\frac{40}{tan 30}\)
= \(\frac{40}{1\sqrt{3}}\)
= 40\sqrt3m
Source: Myschool Past Questions Archive (Record #30850)