Geometry and measurement

Regular polygon calculator

Applies to a regular polygon with equal sides and angles.

Your numbers

Use the units shown. Results update as you change valid inputs.

YOUR RESULT

Applies to a regular polygon with equal sides and angles.

THE NUMBERS, EXPLAINED

How to use this calculator.

Applies to a regular polygon with equal sides and angles.

Start with your inputs

Enter sides, side length. Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.

InputExample value
Sides6
Side length2

A worked example

With the example inputs above, area is 10.392305. Change the inputs to explore your own scenario.

Putting the example numbers into the formula

Area
(6) × (2) × (2) ÷ (4 × tan(π ÷ (6))) = 10.392305

Perimeter
(6) × (2) = 12

Interior angle (degrees)
((6)-2) × 180 ÷ (6) = 120

All results for the example inputs above
ResultExample answer
Area10.392305
Perimeter12
Interior angle (degrees)120

How this is calculated

Area

a × b × b ÷ (4 × tan(π ÷ a))

Perimeter

a × b

Interior angle (degrees)

(a-2) × 180 ÷ a

Symbols and units
a
Sides
b
Side length

Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.

Calculation steps and notation

tan uses an angle in radians. Convert degrees by multiplying by π/180.

π is the circle constant, approximately 3.141592653589793.

Assumptions and limits

Applies to a regular polygon with equal sides and angles.

Calculations use the values you enter. Blank or invalid inputs show an error instead of silently substituting zero. Results are displayed to useful precision; calculations retain the underlying numeric precision.

Questions about this tool

What does the result tell me?

Area; Perimeter; Interior angle (degrees). The result applies to the method and inputs described above. Check the units and assumptions before using it in a decision.

Why might another calculator differ?

Differences in units, rounding, timing or model definitions can produce different answers. Compare the input definitions and the method, rather than only the final number. For this tool: Applies to a regular polygon with equal sides and angles.

Are my inputs stored or sent to AI?

Calculations on this page happen in your browser. The separate AI question finder sends its submitted conversation to OpenAI; these calculator fields are not sent. Favourites and recent tool names are stored locally. A shared link contains the inputs you choose to include.

Further reading

OpenStax: Prealgebra ↗

Background reading; this does not imply endorsement or independent review of SumFizz.

Review status

Software example and browser checks are recorded in our quality report. No external expert review is claimed. Created with coding assistance; calculations run as ordinary browser code.

Read the quality report →