PW Class 6 Maths Notes Chapter 6: Perimeter and Area

A shape can be studied in different ways. You may need to find the length around its boundary or work with the area it covers. Before using formulas, it is important to recognise the shape and understand which measurement is required.

The PW Class 6 Perimeter and Area Notes cover open and closed shapes, the concept of perimeter, and formulas for finding the perimeter and area of different shapes. You can revise the perimeter of rectangles, squares and polygons, along with the area of squares, rectangles and triangles.

What Are Open and Closed Shapes?

Shapes can be identified as closed shapes or open shapes depending on whether their boundaries are complete.

• Closed Shapes

A closed shape has a complete boundary. The ends meet to enclose the shape.

• Open Shapes

An open shape does not have a completely closed boundary. Its ends do not meet.

Recognising whether a shape is open or closed provides the starting point for working with its boundary.

What Is Perimeter?

The perimeter of a shape is the length of its boundary.

To find a perimeter, you work with the lengths around the outside of the shape. The method depends on the shape and the lengths of its sides.

What Are the Perimeter Formulas for a Rectangle and Square?

Rectangles and squares have different side relationships, so their perimeter formulas are written differently.

How Is the Perimeter of a Polygon Found?

For a polygon, the perimeter is obtained by adding the lengths that make up its complete boundary.

Consider the given polygon with boundary lengths:

10 cm, 2 cm, 2 cm, 4 cm, 4 cm, 5 cm, 5 cm and 2 cm

Adding them gives:

Perimeter = 10 + 2 + 2 + 4 + 4 + 5 + 5 + 2

Perimeter = 34 cm

This calculation follows the entire boundary of the polygon and adds each length once.

What Is Area?

The area of a shape tells us how much space it covers. While perimeter deals with the length of a shape's boundary, area focuses on the space enclosed within that boundary.

The method used to find the area depends on the shape. For a square, rectangle, or triangle, different dimensions are used in their respective area formulas.

Area Formulas

The table below brings the key Class 6 area formulas together with a simple explanation of how each one is used. 

How Can PW Class 6 Notes Help You Revise Perimeter and Area?

The PW Class 6 Perimeter and Area Notes help you keep perimeter and area clear by connecting each measurement with the right shape and formula. You can use them to revise what needs to be measured before solving a question.

• Understand What You Need to Measure

First decide whether you need the boundary of a shape or the space it covers. This helps you choose between perimeter and area instead of mixing up the two concepts.

• Match the Shape with the Right Formula

Use PW notes to connect each shape with its formula. For example, the perimeter of a square is 4a, while the perimeter of a rectangle is 2(a + b).

• Revise Area Formulas Together

Compare the formulas for a square, rectangle, and triangle in one place. This helps you recall when to use a², a × b, or ½ × Base × Height.

• Practise Perimeter Beyond Squares and Rectangles

Perimeter is not limited to shapes with a direct formula. For a polygon, follow the complete boundary and add the length of each side to find the total perimeter.

Complete PW Resources for Class 6 Maths Preparation

After revising the PW Class 6 Perimeter and Area Notes, you can use the related PW Class 6 Maths resources for further study and question practice.

Perimeter and area deal with different measurements of shapes, so identifying what needs to be measured is an important first step. The PW Class 6 Perimeter and Area Notes keep the definitions, perimeter calculations, and area formulas together, making it easier to revisit each concept and formula during revision.