STEP 1 - WRAP RIBBON: Take the ribbon and wrap it around a glass. Mark where the ribbon overlaps itself. Image caption, STEP 2 - CUT CIRCUMFERENCE: Cut the ribbon at the point where it overlaps. You ...

The perimeter of a circle is called the circumference. The shortest distance from the centre to the circumference is called the radius. The line across the centre of a circle is the diameter, this is ...