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Circle Formulas:
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The radius of a circle is the distance from its center to any point on its edge. The diameter is the longest distance from one point on a circle through the center to another point, equal to twice the radius.
The calculator uses these simple formulas:
Explanation: These formulas show the direct relationship between radius and diameter in any circle.
Details: Knowing either the radius or diameter is essential for calculating other circle properties like circumference, area, and for applications in engineering, architecture, and physics.
Tips: Select whether you want to calculate radius from diameter or vice versa, enter the known value (must be positive), and click calculate.
Q1: Can I use this for spheres too?
A: Yes, the same formulas apply to the radius and diameter of spheres.
Q2: What units should I use?
A: Any consistent unit (mm, cm, m, inches, etc.) can be used as long as input and output are in the same units.
Q3: Is diameter always twice the radius?
A: Yes, by definition in Euclidean geometry, the diameter is always exactly twice the radius for any circle.
Q4: Which is more commonly used?
A: It depends on the application. Radius is often used in formulas, while diameter is commonly used in measurements.
Q5: How precise should my measurements be?
A: For practical purposes, 2-3 decimal places are usually sufficient, but use more for precision engineering.