Regular Pentagon Apothem Calculator for shape comparison, sketching, and formula checking when you want a fixed formula answer without improvising the math by hand.
Informational calculator only. Verify important outputs independently before legal, tax, medical, engineering, safety-critical, contractual, employment, or compliance use.
Enter job values, review the estimate, then use the decision hints before ordering or quoting.
apothem = side / (2 x tan(pi / 5))Use the regular-polygon apothem relationship for a 5-sided shape with equal sides and angles.
This page assumes a regular regular pentagon.
Keep more precision when the output will feed another formula, drawing, coordinate step, or comparison rather than being rounded once and left alone.