CALCULATOR
Regular Decagon Area Calculator
Find area of a regular 10-sided polygon. Example: Side: 2 m gives 30.7768353718 m². Regular polygon only: 10 equal sides and equal interior angles. Irregular shapes excluded. Flat Euclidean shape; stated measurements in displayed units. No waste, thickness, structural suitability or curved-earth claim. Floating point rounding is display only.
Regular polygon only: 10 equal sides and equal interior angles. Irregular shapes excluded. Flat Euclidean shape; stated measurements in displayed units. No waste, thickness, structural suitability or curved-earth claim. Floating point rounding is display only. Derivation: Split into n isosceles triangles; apothem = side/(2 tan(π/n)); area=perimeter×apothem/2. Coefficient folded before AST evaluation.
Accepted inputs: Side: 0.001 to 1,000 m.
How the calculation works
A = n side² /(4 tan(π/n)), n=10
Worked example
With side 2 m, area of a regular 10-sided polygon is 30.77683537 m².
Assumptions and limits
Regular polygon only: 10 equal sides and equal interior angles. Irregular shapes excluded. Flat Euclidean shape; stated measurements in displayed units. No waste, thickness, structural suitability or curved-earth claim. Floating point rounding is display only. Derivation: Split into n isosceles triangles; apothem = side/(2 tan(π/n)); area=perimeter×apothem/2. Coefficient folded before AST evaluation.