Perimeter Calculator
Find the perimeter or circumference of rectangles, squares, triangles, circles and regular polygons.
Perimeter Calculator
Find the perimeter or circumference of rectangles, squares, triangles, circles and regular polygons.
How to use the Perimeter Calculator
- Select the shape type.
- Enter the required dimensions.
- Click Calculate.
Formula
Rectangle: P = 2(w + h)
Square: P = 4a
Triangle: P = a + b + c
Circle: C = 2πr
Regular polygon: P = n × s
Example
Regular hexagon with side 5: P = 6 × 5 = 30
Step-by-step calculation
- Select "Regular polygon".
- Enter sides: 6, side length: 5.
- Perimeter = 6 × 5 = 30.
- Result: 30 units.
Real-world uses
- Fencing and border calculations.
- Frame and trim measurement.
- Garden bed edging.
Common mistakes
- Confusing perimeter with area.
- For regular polygons, using the wrong number of sides.
- For triangles, forgetting that all three sides may differ.
Frequently asked questions
What is a regular polygon?
A polygon with all sides equal and all angles equal. Examples: equilateral triangle, square, regular pentagon.
Can I find the area too?
Yes, for some shapes like square and triangle, the result also shows the area.
How is circle circumference different from perimeter?
Circumference is the perimeter of a circle. Same concept, different name.