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Lesson 1: Perimeter

# Find perimeter by counting unit squares

Practice finding perimeter by counting unit squares.  We will start with rectangles and then try some irregular shapes.

## Rectangles

Problem 1A
Each square on the grid is 1 unit square.
What is the perimeter of the rectangle?
A rectangle with 1 column and 4 rows on a grid. There are 4 unit squares in the rectangle.
units

Problem 1B
Each square on the grid is 1 unit square.
What is the perimeter of the square?
A square with 4 rows and 4 columns shown on a grid. There are 16 unit squares in the square.
units

## Irregular shapes

Problem 2A
Each square on the grid is 1 unit square.
What is the perimeter of the shape?
A figure with 3 rows and 2 columns of 4 unit squares connected together on a grid. The top row has 2 columns of unit squares and the bottom 2 rows each have 1 unit square.
units

Problem 2B
Each square on the grid is 1 unit square.
What is the perimeter of the shape?
A figure of 5 rows and 4 columns of 16 unit squares connected together on a grid. The top row has 2 columns of unit squares, the second, third, and fourth rows have 4 columns of unit squares, and the bottom row has 2 columns of unit squares.
units