Third graders learn to measure the distance all the way around a shape by adding up its side lengths, and to tell perimeter apart from the space inside.
Students will be able to…
Before you can fence a yard or frame a picture, you need to know how far it is around the edge. How do we measure the distance around a shape?
Project this and answer each question about finding the perimeter of a shape — read the explanation after each one.
Tap any phase to open the teacher moves and student actions.
You want to put a fence around a garden. How much fence do you need?
Students answer questions about finding perimeter.
Students find perimeter of several shapes.
Students draw a shape to a target perimeter.
Students reflect on perimeter vs area.
Aligned to the Common Core State Standards for Mathematics.
Solve real-world and mathematical problems involving perimeters of polygons, including finding an unknown side length.
Understand that shapes in different categories may share attributes (such as four sides).
Apply the area and perimeter formulas for rectangles in real-world and mathematical problems.
Use appropriate tools strategically when measuring.
Preview the three formative checks. Tap “Sample answer” to see what mastery looks like — hide them before you print for students.
Have students choose a target perimeter, draw a shape that fits it, and check by adding the side lengths. A printable perimeter worksheet is in the Mathematics library.
Tap a card to flip it, then rate whether you knew it. Built from this lesson’s vocabulary.
A quick self-check with instant feedback, drawn from this lesson’s key terms.
A print-and-go review sheet with a built-in answer key. Tap “Show answer key” to reveal answers, or print the clean version for students.