Circle Calculator
Calculate radius, diameter, circumference, and area of a circle by entering any one value.
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Select the known value and enter it below to calculate the other properties of the circle.
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Understanding Circle Properties
A circle is a fundamental shape in geometry defined as the set of all points in a plane that are at a constant distance (the radius) from a central point. Key properties include:
- Radius (r): The distance from the center to any point on the circle.
- Diameter (d): The distance across the circle through the center, equal to 2r.
- Circumference (C): The distance around the circle, calculated as \(C = 2\pi r\) or \(C = \pi d\) .
- Area (A): The space enclosed within the circle, calculated as \(A = \pi r^2\) .
This calculator helps you quickly find these values, making circle calculations easy and efficient for various applications in mathematics, engineering, and everyday life.