geometry calculator

Regular Pentagon Circumradius Calculator

Regular Pentagon Circumradius Calculator for layout notes, drafting, and classroom geometry when you want a fixed formula answer without improvising the math by hand.

Estimate

Enter job values, review the estimate, then use the decision hints before ordering or quoting.

Estimate Results

Enter values to see the result.

Formula

circumradius = side / (2 x sin(pi / 5))

This formula measures the distance from the center of a regular regular pentagon to any vertex.

All sides and interior angles should be equal for the formula to fit.

Example

6 units gives Circumradius 5. 1039.

Check

Mixing units, scales, or coordinate conventions across side length before calculating circumradius.
Rounding too early when the result still feeds another geometry or algebra step.

Next Step

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Important Use Notice

Informational calculator only. Verify important outputs independently before legal, tax, medical, engineering, safety-critical, contractual, employment, or compliance use.