Perimeter Calculator

How to Calculate Perimeter

Perimeter is the distance around the outside of a shape. The method for calculating perimeter varies depending on the shape. Here's a guide on how to calculate perimeter for different shapes:

Perimeter Formulas

• Circle: \(P = 2\pi r\), where \(r\) is the radius
• Square: \(P = 4s\), where \(s\) is the side length
• Rectangle: \(P = 2(l + w)\), where \(l\) is length and \(w\) is width
• Triangle: \(P = a + b + c\), where \(a\), \(b\), and \(c\) are the side lengths

Calculation Steps

1. Identify the shape you're working with.
2. Measure or note the required dimensions (radius, side length, etc.).
3. Use the appropriate formula for the shape.
4. Substitute the measured values into the formula.
5. Perform the calculation to find the perimeter.

Example Calculations

Circle

For a circle with radius 5 units:

\(P = 2\pi r = 2\pi(5) \approx 31.42\) units

Square

For a square with side length 4 units:

\(P = 4s = 4(4) = 16\) units

Rectangle

For a rectangle with length 6 units and width 3 units:

\(P = 2(l + w) = 2(6 + 3) = 2(9) = 18\) units

Triangle

For a triangle with sides 3, 4, and 5 units:

\(P = a + b + c = 3 + 4 + 5 = 12\) units

Visual Representation

This diagram illustrates the four shapes discussed: circle, square, rectangle, and triangle. The perimeter of each shape is the length of its outer boundary.