Answer: The Radius is the distance from the center outwards. The Diameter goes straight across the circle, through the center. The Circumference is the distance once around the circle.
The formula for calculating the radius is different from calculating the diameter
624 divided by 10 gives you 62.4(miles per hour) 660 divided by 12 gives you 55(miles per hour). So Nancy’s rate was 62.4 miles per hour & Rebecca’s rate was 55 miles per hour. That would be 62.4/55