Circular segment with $r = 9$ units, $\theta = 90^\circ$

Circle with radius $r = 10$ units

Circular segment with $r = 4$ units, $\theta = 30^\circ$

Circular segment with $r = 6$ units, $\theta = 45^\circ$

Circular segment with $r = 8$ units, $\theta = 90^\circ$