Given that the 3 arcs are congruent, it means they have the same angle.
A circle measures 360 degrees, thus, let us divide it into three parts to get the arc length of the 3 arcs RC, CS, and SM which is in Circle A.
360 degrees / 3 = 120 degrees
Again, the three arcs are congruent so the length of arc RC is 120 degrees, same with arcs CS and SM.
