# Lesson Plan: Perimeter of Rectangles and Squares Mathematics • 3rd Grade

This lesson plan includes the objectives, prerequisites, and exclusions of the lesson teaching students how to find the perimeters of rectangles and squares using multiplication, write equations for the perimeter, and recognize the formula for calculating the perimeter of these shapes.

#### Objectives

Students will be able to

• write the formula for the perimeter of a rectangle in words,
• write the formula for the perimeter of a square in words,
• write equations to describe and find the perimeter of a rectangle or square,
• find missing side lengths of rectangles and squares given the perimeter,
• compare perimeters of rectangles and squares.

#### Prerequisites

Students should already be familiar with

• finding the perimeters of rectangles and squares by measuring,
• adding and subtracting whole numbers within 1,000,
• multiplying and dividing whole numbers with up to 2 digits by 1-digit numbers.

#### Exclusions

Students will not cover

• congruence of line segments,
• decimals or fractions,
• perimeters greater than 1,000 units.