Answer:
37.14 units
Explanation:
the whole circumference of a circle is 2×pi×r
a whole circle rotates 360 degrees (one time all around).
so, the length of the arc for a full trip (360 degrees) around a circle is the stated 2×pi×r.
now, if we go only for a part of that full trip angle, the arc is only the corresponding part of the circumference.
in our example here, r (radius) = QR = 19 units
and we only go along the circle for 112 degrees out of the full 360 (112 parts of the whole 360).
so the arc QS = 2×pi×19 × 112/360 = 37.14 units