Videos, examples, and solutions to help Grade 3 students learn how to determine the perimeter of regular polygons and rectangles when whole number measurements are missing.

Common Core Standards: 3.G.1

Related Topics:

Lesson Plans and Worksheets for Grade 3, Lesson Plans and Worksheets for all Grades, More Lessons for Grade 3, Common Core For Grade 3

New York State Common Core Math Module 7, Grade 3, Lesson 14

Application Problems

A rectangular sheep pen measures 5 meters long and 9 meters wide. The perimeter of the cow pen is double the perimeter of the sheep pen. What is the perimeter of the cow pen?

Concept Development

Problem 1: Find perimeter of rectangles with missing side lengths.

Problem 2: Find the perimeter of regular polygons with one side length given.

1. Label the unknown side lengths of the regular shapes below. Then find the perimeter of each shape.

2. Label the missing side lengths of the rectangle below. Then find the perimeter of the rectangle.

3. David draws a regular octagon and labels a side length as shown below. Find the perimeter of David’s octagon.

4. Paige paints an 8 inch by 9 inch picture for her mom’s birthday. What is the total length of wood that Paige needs to make a frame for the picture?

5. Mr. Spooner draws a regular hexagon on the board. One of the sides measures 4 centimeters. Giles and Xander find the perimeter. Their work is shown below. Whose work is correct? Explain your answer.

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