A wheel rotates 3 times. What is its angular displacement?

The angular displacement would be 6 Pi radians or 1080 degrees.

Explanation:

Every individual rotation is 2 Pi (this applies to anything regardless of radius).

Since there are three rotations you are going to multiply 2 Pi by 3.

This will give you 6 Pi which you can convert to equal 1080 degrees (1 Pi = 180 degrees).

The wheel has rotated through an angular distance of 6π radians, or 1,080 degrees.

Its angular displacement is zero, because its initial and final positions are the same ... there's zero angle between them.