When to use this calculator
Count all vertex-to-vertex diagonals in a polygon. Counts connections between non-adjacent vertices of a simple polygon.
Explore the quadrilateral & polygon calculators for other questions in this topic. For a related calculation, use the Polygon Interior Angle Sum Calculator: Find the sum of all interior angles in a simple polygon.
PUTTING IT INTO PRACTICE
Polygon Diagonal Count: a worked example
The values below are an illustrative example, not a recommendation. Replace them with measurements or assumptions that match your question.
| Input | Example value |
|---|---|
| Sides (integer) | 6 |
| Result | 9 diagonals |
- Check the input labels and enter the example values above.
- Apply the relationship: Diagonals = n(n−3)/2.
- The result is 9 diagonals, rounded for display.
How to interpret your result
Counts connections between non-adjacent vertices of a simple polygon.
A perimeter measures the outline; area measures the enclosed surface. Regular polygon tools assume equal sides and angles. For a parallelogram or trapezoid, use the height perpendicular to the selected base.
Frequently asked questions
What does regular polygon mean?
It is a polygon with all sides equal and all interior angles equal.
When is the polygon diagonal count calculator useful?
Count all vertex-to-vertex diagonals in a polygon. Counts connections between non-adjacent vertices of a simple polygon.
How do I use the polygon diagonal count calculator?
Enter sides (integer). The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
Diagonals = n(n−3)/2.
What should I check before using the result?
Counts connections between non-adjacent vertices of a simple polygon.
How are results rounded?
Scalar numbers display up to six decimal places, with scientific notation for very large or small values. Text, fraction, date and schedule outputs use the format described on the tool. Intermediate calculations use JavaScript floating-point arithmetic. Keep sensible precision for your measurements.
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