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√3m/3 B. 5m C. 10√3m/3 D. 5√3m E. 10m
Correct Answer: 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) ⇒ \(x = \frac{5}{sin60}\) \(x = \frac{10\sqrt{3}}{3}m\)
