Question

A ladder is leaning against a vertical wall makes an angle of 20° with the ground. The foot of the ladder is 3 m from the wall. Find the length of ladder.

Answer 1

Answer:

Let AC denote the ladder and B be foot of the wall.

Let the length of the ladder AC be x metres.

Given that ∠CAB=60

∘

and AB=3.5m

In the right △CAB,cos60

∘

=

AC

AB

⇒AC=

cos60

∘

AB

∴x=2×3.5=7m

Thus, the length of the ladder is 7m.