Given that $x=180^\circ$x=180° represents half a circle, what fraction of the circumference of the unit circle does $x=60^\circ$x=60° represent?

Given that $x=180^\circ$x=180° represents half a circle, what fraction of the circumference of the unit circle does $x=225^\circ$x=225° represent?

What fraction of the circumference of the unit circle does $x=540^\circ$x=540°^{ }represent?

What fraction of the circumference of the unit circle does $s=450^\circ$s=450° represent?