Big Nate by Lincoln Peirce for January 11, 1991
Nate: Dad, what's the difference between "radius, diameter and circumference?" Dad: Well, let's see...radius is the distance across...no, wait a minute...say you have a circle and you...or would it be a sphere? Ok, let's say you're in the middle of a circle...the diameter is the length...no, hold it. Nate: I'll just go stand in the street...maybe some passing motorist can help me.