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To measure a circle's circumference, find the circle's diameter, then multiply the diameter by pi to find the circumference. If you only have the radius, multiply it by two to find the circle's diameter. More »
To measure the circumference of a circle, first measure the diameter and multiply that number by the mathematical constant pi. The diameter is a straight line that goes from one side of the circle to the other and passes... More »
The circumference of a circle is calculated by multiplying pi by the diameter, or 2 pi times the radius. The diameter or radius value is required to calculate circumference. More »
Pitch circle diameter is a term used to describe the centerline diameter of a circular bolt spacing, the diameter of theoretical friction discs that would transmit the same velocity ratio as two meshing gears, or the dia... More »
To determine the area of a circle from its diameter, divide the diameter by two, square it and multiply by π. The formula for calculating the area of a circle is: A = πr2, where r is the radius of the circle. More »
One can calculate the diameter of a circle mathematically if the circumference or the area of the circle is known. If the location of the center of the circle is known, then the circle's diameter can be measured with a r... More »
If the circumference or the area of a circle is known, pi can be used to find the diameter and the radius of that circle. Likewise, if the radius or diameter is known, pi can be used to find out the circumference or the ... More »

Amazon Prime Benefits
Free 2day shipping, streamingvideo, music, photo storage & more.

Learn More About Alexa
Handsfree voice control for music,calling, smart home devices & more.

Shop Amazon Fire Tablets
Tablets designed for entertainmentat an affordable price.

Explore Amazon Smart Home
Shop for smart home devices thatwork with Alexa. See our guide too.

Meet the Fire TV Family
See our devices for streaming yourfavorite content and live TV.

Shop Echo & Alexa Devices
Play music, get news, control yoursmart home & more using your voice.