Question

A circle has a radius of 6 in.

Answer 1

Answer:

$\frac{3\pi }{2}$

Proof (Picture):

Answer 2

This is the concept of perimeter of circles, the arc length of the circle will be given by:
(theta)/360*pi*diameter
diameter=2*radius
but;
radius=6 in
diameter=2*6=12 inches
theta=45°
Hence, the arc length will be:
45/360*π*12
=(3π)/2