Measure a Radius Accurately

In this cup or bowl modeling project, it is important you measure the radius of both top and bottom circular openings accurately. [br][br]Please follow these steps to do so.
Trace the opening of the circular cup or bowl on a piece of paper.
Plot two points A and B anywhere on the circle.
Fold point A directly on top of point B. Crease sharply. Then unfold.
Plot two new points C and D on the circle.
Fold point C directly on top of point D. Crease sharply. Then unfold.
Note where your two fold lines intersect. This is the center of your circle. You can now easily measure its radius.

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