Polygon Calculator: Accurate Results for Regular Polygons

Use this polygon calculator to measure regular shapes fast. It focuses on equal sides and equal angles. Enter two values and get clear results. The steps match the fields on this page. Simple and reliable.

Why Use Our Polygon Calculator?

You need quick geometry checks and sound numbers. This polygon calculator returns perimeter and area. It also reports angle measures. It supports triangles, squares, pentagons, and more. One entry per field, one click for results. It saves time and reduces errors in your work.

How Does It Work?

Enter the number of sides. Enter a side length. The calculator applies formulas for regular polygons. Perimeter equals sides multiplied by length. The apothem helps compute the area. The apothem is the center to side midpoint distance. The tool also finds interior angles. It also finds exterior angles. It also finds the central angle. It shows the inradius. It shows the circumradius. It also shows the sum of interior angles.

Key Features

This polygon calculator reports these values and explains what they mean.

• Perimeter: Total distance around the shape.
• Area: Space inside the shape, found from apothem and perimeter.
• Interior Angle: Angle inside at each corner.
• Exterior Angle: Outer angle at each corner, equals 360 divided by sides.
• Central Angle: Angle at the center between two vertices.
• Apothem (Inradius): Center to side midpoint distance, used for area.
• Circumradius: Center to vertex distance.
• Sum of Interior Angles: Total of all inside angles.

Who Benefits?

Students, teachers, engineers, and designers gain quick checks with this tool. The clear output supports homework, plans, and design reviews.

• Verify a triangle, square, or pentagon in seconds.
• Plan an octagon sign with the right dimensions.
• Estimate tiles for a hexagon layout.
• Check a worksheet answer fast.
• Compare shapes for a logo or icon.

Inputs and Data Entry

Number of Sides is a whole number with a minimum of 3. Examples include 3 for triangle. Use 4 for square. Use 5 for pentagon. Side Length is a positive number. Decimals work for precise values. Choose any unit and keep it the same across fields. Press Enter to calculate or click the button. The tool also shows a shape name for common side counts.

How to Use This Tool

1. Enter the number of sides with a minimum of 3.
2. Enter the side length in your chosen unit.
3. Click Calculate or press Enter.
4. Review the results.

Feel Confident With Every Calculation

This tool supports regular polygons only. All angle values appear in degrees. Length units follow your entry. Area uses square units. The apothem equals the inradius by definition. The circumradius comes from the circumscribed circle. The calculator rounds to two decimals for display. Use precise inputs for higher accuracy. A standard name appears for many side counts.

Keep your units consistent for every field. Try a triangle, a square, or a pentagon to start. Adjust the side length and compare results. This polygon calculator aims for clear and quick answers. Use it now for your next shape task.