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.
- \(\frac{5\sqrt3}{3}\)m
- 5m
-
\(\frac{10\sqrt3}{3}\)m
- 5√3m
- 10m
The correct answer is: 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)
⇒ \(x = \frac{5}{sin60}\)
\(x = \frac{10\sqrt{3}}{3}m\)