Area of Squares and Rectangles

1. What is the area of a rectangle of sides 3 cm by 2 cm?

model diagram
To find out the area of the rectangle, we must find out how many 1-cm squares it is made up of.
model diagram
A 3 cm by 2 cm rectangle is made up of 2 rows of 1-cm squares.
Each row has three 1-cm squares.
The rectangle is made up of six 1-cm squares.
So, the area of the rectangle is 6 cm2.

In other words, the area of the rectangle is the product of its length and breadth.

The longer side of a rectangle is called the length.
The shorter side is called the breadth.

Area of rectangle  =  Length  ×  Breadth

Area of the given rectangle
=  3  ×  2
=  6 cm2

2. What is the area of a 4-cm square?

model diagram
To find out the area of the square, we must find out how many 1-cm squares it is made up of.
model diagram
A 4-cm square is made up of 4 rows of 1-cm squares.
Each row has four 1-cm squares.
The square is made up of sixteen 1-cm squares.
So, the area of the square is 16 cm2.

In other words, the area of the square is the product of its sides.

Area of square  =  Side  ×  Side

Area of the given square
=  4  ×  4
=  16 cm2

3. Caroline wants to build a wall as shown below.
What will be the area of the wall she builds?

model diagram
Area of rectangle
=  Length  ×  Breadth
=  5 m  ×  4 m
=  20 m2

The area of the wall will be 20 m2.

4. A square slice of cheese is 9 cm long.
Find the area of the slice of cheese.

Area of square
=  Side  ×  Side
=  9 cm  ×  9 cm
=  81 cm2

The area of the slice of cheese is 81 cm2.