Diameter (of a circle)

This entry briefly looks at the diameter of a circle. The word “diameter” comes from Greek διάμετρος (diametros), “diameter of a circle”, from δια- (dia-), “across, through” + μέτρον (metron), “measure”. The diameter of a circle is a straight line segment that passes through the center of the circle and whose endpoints lie on the circle. It is also the longest chord of the circle.
Provided you know the radius. The diameter value can be found by doubling the radius.
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…where R is the radius of the circle.
You can also use the circumference of a circle to find the diameter. You simply rearrange the circumference formula.
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…where;

• C is the circumference of the circle
• π is Pi, approximately 3.142

You can also find the diameter provided you know the area of a circle.
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…where;

• A is the area of a circle
• π is Pi, approximately 3.142