we know that
360°/12 hour-----------> 30°/hour
Central angle at 4 .00 is 120 degrees
the radius of a clock is 6/2-----> r=3 in
length of a circumference=2*pi*r-----> 2*pi*3----> 18.84 in
the minor arc at 4 .00 is for a central angle of 120°
so
if 360° (full circle)---------> has a length of 18.84 in
120°----------------------> X
X=120*18.84/360-------> X=6.28 in
the answer is
6.28 in
