Plane Shape Calculator
Local ProcessingArea and length for circles, sectors, annuli, chords, segments, ellipses, trapezoids and regular polygons.
How It Works & Processing Standards
Enter values above to calculate results automatically. Check each input field for guidance and units.
Example: Radius = 2 → 12.566371
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Twelve plane geometry formulas in one tool. Pick the shape and value under "Calculation" and only the needed fields appear.
An ellipse has no exact perimeter formula, so the Ramanujan approximation is used. π is JavaScript Math.PI (15 digits).
What You Can Do
- Circle
- Area πr², circumference 2πr
- Sector and arc
- Arc length, sector area, central angle from an arc length
- Annulus, chord, segment
- Ring area, chord length, circular segment area
- Ellipse, trapezoid, polygon
- Ellipse perimeter (Ramanujan approximation), trapezoid area, regular polygon area and interior angle
How to Use Plane Shape Calculator
- 1Choose a calculationPick one of the twelve.
- 2Enter dimensionsOnly the needed fields show. Angles are in degrees.
- 3Read the resultAreas are in your unit squared, lengths in your unit.
Examples
Common Use Cases
- The area of a round table or flower bed
- Comparing pizza slice (sector) sizes
- The area of hexagonal tiles or polygon parts
Frequently Asked Questions (FAQ)
What if I only know the diameter?
The radius is half the diameter. For a diameter of 20, enter 10.
What unit is the area?
Your length unit squared — cm in gives cm².