多角形計算機

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はじめに

Polygon Calculator — Compute interior angle sums and area of a regular polygon. Enter Number of sides, Side length (optional) to get an instant, accurate result.

計算式

Sum of interior angles = (n−2)×180°. Each interior angle (regular polygon) = sum/n. Area of a regular polygon with side length s = (n×s²) / (4×tan(π/n)).

ステップごとの説明

Enter the Number of sides.
Enter the Side length (optional).
Click Calculate to see your result instantly.

実例

Example: With Number of sides = 6, Side length (optional) = 4, the Polygon Calculator gives Interior Angle Sum: 720, Each Interior Angle: 120, Area: 41.5692.

よくある質問

Does the interior angle sum depend on side length?

No, the sum of interior angles depends only on the number of sides, n.

Is the area formula valid for any polygon?

It assumes a regular polygon, where all sides and angles are equal.

What inputs does the Polygon Calculator need?

You'll need to provide: Number of sides, Side length (optional). All fields use sensible defaults, so you can see a working example immediately and then adjust the values to match your own numbers.

How accurate is the Polygon Calculator?

The Polygon Calculator applies the formula exactly as calculated — Sum of interior angles = (n−2)×180°. Each interior angle (regular polygon) = sum/n. Area of a regular polygon with side length s = (n×s²) / (4×tan(π/n)). — so results are precise for the inputs you provide. Accuracy depends on entering correct, realistic input values.

Is the Polygon Calculator free to use?

Yes, the Polygon Calculator is completely free, requires no signup, and runs instantly in your browser.