Question

a ladder 15 metres long just reaches the top of a vertical wall.If the ladder makes an angle of 60 with the wall,find the height of the wall

Answer 1

$\bf\huge{\underline{\underline{Question}}}$

A ladder 15 metres long just reaches the top of a vertical wall.If the ladder makes an angle of 60° with the wall, find the height of the wall.

$\bf\huge{\underline{\underline{Solution}}}$

Given, height of the ladder = 15 m

Let the height of the vertical wall = h

Because, and the ladder makes an angle of 60° with the wall i.e., θ = 60°

In ∆QPR,

cos60° = $\dfrac{PR}{PQ}$ = $\dfrac{h}{15}$

=> $\dfrac{1}{2}$ = $\dfrac{h}{15}$

=> h = $\dfrac{15}{2}$ m

Hence, the required height of the wall is $\dfrac{15}{2}$ m.