Perimeter (In Steps)

Learning Objectives Define perimeter as the distance around a shape. Calculate the perimeter of a polygon by adding the lengths of all its sides. Use multiplication to find the perimeter of a square given one side length. Calculate the perimeter of a rectangle given its length and width. Find the length of an unknown side of a polygon when given the perimeter and the other side lengths. Solve real-world problems involving perimeter. Have you ever wanted to build a fence for your toy animals or put a ribbon around a birthday card? 🎁 That's perimeter! In this lesson, we will learn how to measure the distance around the outside of a shape. This is a very useful skill called finding the perimeter. We'll learn the steps to find the perimeter for any shape with straigh...

TermDefinitionExample PerimeterThe total distance around the outside edge of a flat (2D) shape.If you walk all the way around a square park, the total distance you walked is the park's perimeter. SideOne of the straight lines that make up a flat shape, like a square or triangle.A triangle has 3 sides. A rectangle has 4 sides. PolygonA flat, closed shape with three or more straight sides.Triangles, squares, rectangles, and pentagons are all polygons. RectangleA polygon with 4 sides where opposite sides are equal in length.A door, a book, and a tablet screen are often shaped like rectangles. SquareA special rectangle where all 4 sides are exactly the same length.A cheese cracker or a single tile on the floor can be a square. Unit of LengthA standard measurement for how long something i...

Perimeter of Any Polygon P = \text{side}_1 + \text{side}_2 + \text{side}_3 + ... To find the perimeter of any shape with straight sides, you simply add the lengths of all the sides together. Perimeter of a Square P = 4 \times s Since all four sides (s) of a square are equal, you can find the perimeter by multiplying the length of one side by 4. Perimeter of a Rectangle P = l + w + l + w \text{ or } P = 2 \times (l + w) For a rectangle, you add the length (l) and width (w) together, and then double that sum because there are two equal lengths and two equal widths.