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Enter the number of sides and side length to quickly calculate the area of any regular polygon. Ideal for geometry students and engineering calculations.

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Manually applying trigonometric formulas to calculate the area of a regular polygon can be tedious and prone to errors. Based on the universal polygon area formula, this tool allows you to input the number of sides (n) and the side length (s) to instantly output the precise area. A regular polygon is a flat geometric figure with all sides and interior angles equal. The area formula is: Area = (n × s²) / (4 × tan(π/n)). This is derived by dividing the polygon into n congruent isosceles triangles and summing their areas.
Q: How does the tan function in the formula handle non-standard angles?
A: The tool's built-in math library automatically calculates the tangent for all angles, including non-standard angles obtained by dividing 180° by the number of sides.
Q: Is there a maximum limit for the number of sides?
A: Theoretically, there is no strict upper limit. However, calculation precision may be affected by floating-point limitations when the number of sides is extremely large. We recommend keeping it within a practical range (3 to 1,000 sides).
Ensure the number of sides is an integer ≥ 3 and the side length is a positive number. Minor floating-point errors may occur in the results. This tool does not support irregular polygons. There are no privacy concerns with sensitive data, as all calculations are performed locally in your browser.
For engineering applications, we recommend keeping track of your units: if you input the side length in millimeters, the result will be in square millimeters. Typical examples: A regular hexagon (n=6) with a side length of 10 cm has an area of approximately 259.81 cm²; a regular dodecagon (n=12) with a side length of 5 m has an area of approximately 279.9 m². In practical applications, note the relationship between regular polygons and circle approximations—as the number of sides approaches infinity, the polygon's area approaches the area of a circle.