Question

A ladder leans against a wall making an angle of measure ${60}^{\circ }$ with the ground. If the foot of the ladder is $3$ metre away from the wall, then the length of the ladder is ..... metre.

• A. $\frac{3}{2}$
• B. $3\sqrt{3}$
• C. $6$
• D. $\frac{3\sqrt{3}}{2}$

Answer 1

The correct option is C $6$

Given distance between the foot ofthe ladder and wall is $3m$

Let the length of ladder be $l$

$⟹\cos {60}^{\circ }=\frac{3}{l}$

$⟹l=3\text{sec}{60}^{\circ }$

$⟹l=6$

So the length of the ladder is $6m$