Question

A ladder is placed along a wall such that its upper end is resting against a vertical wall. The foot of the ladder is 20 m from the wall and the ladder is making an angle of ${60}^{\circ }$ with the ground. Find the height, upto which the ladder reaches. [2 MARKS]

Answer 1

Let AB be the wall and


AC be the ladder, which is placed against the wall. If foot is 20 m away from the wall i.e. BC = 20 m

Let $AB=x$

In right $\Delta ABC$,

$tan\theta =\frac{AB}{BC}\Rightarrow tan{60}^{\circ }=\frac{x}{20}$

$\therefore x=20\times tan{60}^{\circ }=20\sqrt{3}m$

$=20\left(1.732\right)$

$=34.64m$ [1 MARK]