Mathematics

A ladder leans against a vertical wall at an angle 60° to the wall, if…

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: 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)