Question

A ladder 15 meters long just reaches the top of a vertical wall. If the ladder makes an angle of 60° with the wall, then the height of the wall will be ____________.

Options

• 7.5 m

• 7.7 m

• 8.5 m

•  8.8 m

Answer 1

A ladder 15 meters long just reaches the top of a vertical wall. If the ladder makes an angle of 60° with the wall, then the height of the wall will be 7.5 m.

Explanation:

Given that the height of the ladder is 15 m

Let the height of vertical be = h

And the ladder makes an angle of elevation 60° with the wall

In triangle QPR

`"cos"  60^circ = "PR"/"PQ"`

`1/2 = "h"/15`

`=> "h" = 15/2`

`=> "h" = 7.5  "m"`