Navigation

K-5 Grade 3 Unit 7 Lesson 8

Gradeband

•K-5 Math 6-8 Math 9-12 Math

Course

Kindergarten Grade 1 Grade 2 •Grade 3 Grade 4 Grade 5

Unit

Unit 1 Unit 2 Unit 3 Unit 4 Unit 5 Unit 6 •Unit 7 Unit 8

Lesson

Lesson 1 Lesson 2 Lesson 3 Lesson 4 Lesson 5 Lesson 6 Lesson 7 •Lesson 8 Lesson 9 Lesson 10 Lesson 11 Lesson 12 Lesson 13 Lesson 14 Lesson 15

K-5
6-8
9-12

Kindergarten
Grade 1
Grade 2
Grade 3
Grade 4
Grade 5

Unit 1
Unit 2
Unit 3
Unit 4
Unit 5
Unit 6
Unit 7
Unit 8

Lesson 1
Lesson 2
Lesson 3
Lesson 4
Lesson 5
Lesson 6
Lesson 7
Lesson 8
Lesson 9
Lesson 10
Lesson 11
Lesson 12
Lesson 13
Lesson 14
Lesson 15

Lesson | Loading...

Sign in to access protected content and invite other educators

Sign in using your existing Kendall Hunt account. If you don’t have one, create an educator account.

Curriculum

IM K-5 Math
IM 6-8 Math
IM 9-12 Math

Professional Learning

Illustrative Mathematics® has operated as an independent 501(c)3 non-profit organization since 2013.

©2024 Illustrative Mathematics®. Licensed under CC BY-NC 4.0.

The Illustrative Mathematics name and logo are not subject to the Creative Commons license and may not be used without the prior and express written permission of Illustrative Mathematics.

This site includes public domain images or openly licensed images that are copyrighted by their respective owners. Openly licensed images remain under the terms of their respective licenses. See the image attribution section for more information.

Settings

Language

Audience

Not all roles available for this page.

Assessment Access

Sign in to view assessments and invite other educators

Sign in using your existing Kendall Hunt account. If you don’t have one, create an educator account.

English
Español

teacher
student
family

Lesson 8

Warm-up Activity 1 Activity 2

Unit 7, Lesson 8

Find the Perimeter

Grade 3

Warm-up

Find the value of each expression mentally.

Activity 1

What do you notice? What do you wonder?

Diagram. 2 rectangles. One on a 5 by 3 dot grid, one with sides marked 5 and 3.

Find the perimeter of each shape. Explain or show your reasoning.

Activity 2

Find the perimeter of this rectangle. Explain or show your reasoning.
All the short sides of this figure are the same length, and all the angles are right angles. Find the perimeter of the figure. Explain or show your reasoning.
This octagon has all equal side lengths. Find the perimeter of the octagon. Explain or show your reasoning.