CALCULATOR
Regular Pentagon Area Calculator
pentagon. Example: Side: 2 m gives 6.88190960236 m². Regular pentagon only: 5 equal sides and equal interior angles. Computes area, not arbitrary polygon reconstruction. Flat Euclidean geometry in the stated units. No waste, thickness, structural advice or curved-earth inference. Only the stated forward job is supported; display rounding does not change the calculation.
Regular pentagon only: 5 equal sides and equal interior angles. Computes area, not arbitrary polygon reconstruction. Flat Euclidean geometry in the stated units. No waste, thickness, structural advice or curved-earth inference. Only the stated forward job is supported; display rounding does not change the calculation. Derivation: Split into equal isosceles triangles; apothem is side/(2tan(π/n)).
Accepted inputs: Side: 0.001 to 1,000 m.
How the calculation works
A = 5s²/(4 tan(π/5))
Worked example
With side 2 m, pentagon is 6.881909602 m².
Assumptions and limits
Regular pentagon only: 5 equal sides and equal interior angles. Computes area, not arbitrary polygon reconstruction. Flat Euclidean geometry in the stated units. No waste, thickness, structural advice or curved-earth inference. Only the stated forward job is supported; display rounding does not change the calculation. Derivation: Split into equal isosceles triangles; apothem is side/(2tan(π/n)).