Perimeter Calculator
• Square: P = 4s
• Rectangle: P = 2(l + w)
• Triangle: P = a + b + c
• Circle: P = 2πr (circumference)
• Pentagon: P = 5s (regular)
• Hexagon: P = 6s (regular)
Perimeter = 2(8 + 5)
= 2 × 13
= 26 cm
Square with same perimeter:
Side = 26 ÷ 4 = 6.5 cm
🔗 Related Calculators
📐 Formula
• Square: P = 4s
• Rectangle: P = 2(l + w)
• Triangle: P = a + b + c
• Circle: P = 2πr (circumference)
• Pentagon: P = 5s (regular)
• Hexagon: P = 6s (regular)
📝 Example Calculation
Perimeter = 2(8 + 5)
= 2 × 13
= 26 cm
Square with same perimeter:
Side = 26 ÷ 4 = 6.5 cm
About Perimeter
Perimeter is the total distance around the boundary of a two-dimensional shape. It represents the length you would travel if you walked around the outside edge of the shape. This calculator supports multiple shapes and provides both perimeter and area calculations.
Perimeter Formulas by Shape
- Rectangle: P = 2(l + w) or P = 2l + 2w
- Square: P = 4s
- Circle: C = 2PIr or C = PId (called circumference)
- Triangle: P = a + b + c
- Parallelogram: P = 2(a + b)
- Trapezoid: P = a + b + c + d
- Regular Polygon: P = n * s (n = number of sides, s = side length)
How to Use This Calculator
- Select the shape from the dropdown menu
- Enter the required dimensions for that shape
- Click "Calculate" to get the perimeter
- View detailed results including area and other properties
Understanding Perimeter vs Area
While perimeter measures the distance around a shape (linear measurement), area measures the space inside the shape (square measurement). A shape can have a large perimeter but small area, or vice versa. For example, a long thin rectangle has a larger perimeter relative to its area compared to a square with the same area.
Frequently Asked Questions
What is perimeter?
Perimeter is the total distance around the outside of a two-dimensional shape. It is the sum of all the sides of the shape. For example, the perimeter of a rectangle is found by adding all four sides together.
What is the difference between perimeter and area?
Perimeter is the distance around the outside of a shape (measured in linear units like meters or feet), while area is the amount of space inside the shape (measured in square units like square meters or square feet). Perimeter is one-dimensional, area is two-dimensional.
How do you calculate the perimeter of a rectangle?
The perimeter of a rectangle is calculated using the formula P = 2(l + w), where P is perimeter, l is length, and w is width. You can also use P = 2l + 2w. Simply add the length twice and the width twice.
What is the perimeter formula for a circle?
For a circle, the perimeter is called the circumference. The formula is C = 2PIr or C = PId, where C is circumference, r is radius, and d is diameter. The circumference is approximately 6.28 times the radius (2PI ≈ 6.28).
How do you find the perimeter of an irregular shape?
For an irregular shape, measure each side individually and add all the measurements together. There is no single formula for irregular shapes - you must know the length of every side and sum them all.
What are real-world applications of perimeter?
Perimeter calculations are used for fencing yards or gardens, framing pictures, installing baseboards or crown molding, laying out running tracks, calculating material needed for borders, and determining the length of wire or piping needed for projects.