How do I find the circumference of a circle?

How to find the circumference of a circle: the distance around it is π times the diameter, so C = πd = 2πr, shown by unrolling the circle into a line.

Step-by-step explanation

1. The circumference is the total distance around the edge of a circle. We define it using the radius, which is the distance from the center to the edge.
2. If we take the diameter—which is twice the radius—and 'wrap' it around the circle, we find it fits exactly pi times.
3. To visualize this, imagine 'unrolling' the circle into a straight line. The length of this line is the circumference.
4. The relationship is constant: the circumference equals pi times the diameter, or two times pi times the radius.

This is a real answer from Math Motion AI: the explanation and the animation were made by the site for this question.

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