A ladder leans against a vertical wall at an angle
60^\circ to the wall, if the foot of the ladder is 5 metres
away from the wall, calculate the length of the
ladder.
A
\(\frac{5\sqrt3}{3}\)m
B
5m
C
\(\frac{10\sqrt3}{3}\)m
D
5√3m
E
10m
Verified Correct Answer: C.
Step-by-Step Mathematical Solution
The ladder makes 60^\circ 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)
⇒ \(x = \frac{5}{sin60}\)
\(x = \frac{10\sqrt{3}}{3}m\)
Source: Myschool Past Questions Archive (Record #23172)