In Lesson 8 of Saxon Math Course 1, Grade 6 students learn how to calculate perimeter by adding the side lengths of polygons, including rectangles, triangles, squares, and trapezoids. The lesson also introduces the concept that for regular polygons, the perimeter can be found by multiplying the length of one side by the number of sides. Students practice finding missing side lengths when the perimeter of a shape is known, such as determining a side of a square from its total perimeter.
Section 1
📘 Perimeter
The distance around a shape is its perimeter. To find the perimeter of a polygon, we add the lengths of its sides.
This is your introduction to measuring geometric figures. Next, you’ll tackle worked examples to calculate the perimeter of various shapes, including regular polygons, and solve problems from a new perspective.
Section 2
Perimeter of a square
Since a square has four sides of equal length, its perimeter is four times the side length , so . To find the side length from the perimeter, you can calculate .
A square is a super special shape where all sides are best friends and insist on being the exact same length! So, instead of adding the same number four times, you can just use a quick multiplication shortcut. Finding the length of a side from the perimeter is just doing that same cool trick in reverse. Teamwork for numbers!
Section 3
Perimeter of a regular polygon
A regular polygon has sides that are all the same length. To find its perimeter, multiply the number of sides by the length of one side.
Regular polygons are all about fairness! Every single side is the exact same length. This makes finding the perimeter a total breeze. Instead of adding a long list of the same number over and over again, you can just multiply the number of sides by the length of one side. It is the ultimate mathematical shortcut for these shapes!
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter
Expand to review the lesson summary and core properties.
Section 1
📘 Perimeter
The distance around a shape is its perimeter. To find the perimeter of a polygon, we add the lengths of its sides.
This is your introduction to measuring geometric figures. Next, you’ll tackle worked examples to calculate the perimeter of various shapes, including regular polygons, and solve problems from a new perspective.
Section 2
Perimeter of a square
Since a square has four sides of equal length, its perimeter is four times the side length , so . To find the side length from the perimeter, you can calculate .
A square is a super special shape where all sides are best friends and insist on being the exact same length! So, instead of adding the same number four times, you can just use a quick multiplication shortcut. Finding the length of a side from the perimeter is just doing that same cool trick in reverse. Teamwork for numbers!
Section 3
Perimeter of a regular polygon
A regular polygon has sides that are all the same length. To find its perimeter, multiply the number of sides by the length of one side.
Regular polygons are all about fairness! Every single side is the exact same length. This makes finding the perimeter a total breeze. Instead of adding a long list of the same number over and over again, you can just multiply the number of sides by the length of one side. It is the ultimate mathematical shortcut for these shapes!
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter