Question

Find the length of the red arc. Leave your answer in terms of pi.

Answer 1

Known :

r = 18 m

θ = 90° (because right angle)

Asked :

arc length = ...?

Answer :

Arc length

`= (θ)/(360) * 2\pi r \\ = (90)/(360) * 2 * \pi * 18 \\ = (1)/(4) * 36\pi \\ = 9\pi\: cm`

So, length of the red arc is 9π cm

Hope it helps and is useful :)