Perimeter is the distance around the outside of a shape. It is the sum of all the side lengths of the shape.

Here are the formulas for calculating the perimeter of different shapes:

**Rectangle:**Perimeter = 2 * (length + width)**Square:**Perimeter = 4 * side length**Triangle:**Perimeter = sum of all three sides**Circle:**Perimeter = 2 * π * radius (or π * diameter)

Let's solve some example problems to practice calculating perimeter:

Find the perimeter of a rectangle with a length of 8 units and a width of 5 units.

Perimeter = 2 * (8 + 5) = 2 * 13 = 26 units

What is the perimeter of a square with a side length of 10 inches?

Perimeter = 4 * 10 = 40 inches

Determine the perimeter of a triangle with side lengths of 7 cm, 9 cm, and 12 cm.

Perimeter = 7 + 9 + 12 = 28 cm

Calculate the perimeter of a circle with a radius of 5 meters. (Use π ≈ 3.14)

Perimeter = 2 * 3.14 * 5 = 31.4 meters

Perimeter is the total distance around the boundary of a shape. To find the perimeter, add up all the side lengths of the shape. Use the appropriate formula for different shapes, such as rectangles, squares, triangles, and circles.

Study GuidePerimeter Worksheet/Answer key

Perimeter Worksheet/Answer key

Perimeter Worksheet/Answer key

Perimeter

Geometry (NCTM)

Analyze characteristics and properties of two- and three-dimensional geometric shapes and develop mathematical arguments about geometric relationships.

Precisely describe, classify, and understand relationships among types of two- and three-dimensional objects using their defining properties.

Use visualization, spatial reasoning, and geometric modeling to solve problems.

Use geometric models to represent and explain numerical and algebraic relationships.