The minute hand walked for an hour, and the tip of the minute hand just walked a circle.

Because the length of the minute hand is 20 cm, the radius of this circle is 20 cm.

Walk a full circle every hour and a semicircle every 30 minutes.

Ok, this question is for you to find a circle with a radius of 20cm and find its half circumference.

Circumference =2× radius× π = 2× 20× 3.14 =125.6 (cm)

Half is: 125.6÷2=62.8(cm).