A ladder leans against a vertical wall at an angle
60° to the wall, if the foot of the ladder is 5 metres
away from the wall, calculate the length of the
ladder.
-
A.
5√3m3
-
B.
5m -
C.
10√3m3
-
D.
5√3m -
E.
10m
Correct Answer: Option C
Explanation
The ladder makes 60° inclination with the wall and its foot is 5m away from the wall.
Sketching the diagram, you will see that we have
(sin 60 = frac{5}{x}) (where x is the length of the ladder)
⇒ (x = frac{5}{sin60})
(x = frac{10sqrt{3}}{3}m)