CBSE Class 5 Mathematics Area and Perimeter Assignment

CBSE Class 5 Mathematics-Area and Perimeter (1). Students are advised to refer to the attached assignments and practise them regularly. This will help them to identify their weak areas and will help them to score better in examination. Parents should download and give the assignments to their children for practice.

ub topic: Perimeter

Rectilinear figure

A plane figure made of line segments is called a rectilinear figure. For example, a

triangle, a quadrilateral etc. are rectilinear figures.

Perimeter of a Rectilinear figures:

Definition: The sum of all sides of a rectilinear figure is called its perimeter.

OR

The distance around the edge of a figure is its perimeter.

Explanation: Suraj needs to put a frame around the picture he has made.

To find how much he needs to buy, he takes a string and wraps it around the picture with

a knot in every corner.

This is how the string looks when he takes it off.

(String)

He then measures the string and finds that it is 90cm long. The string shows the length

of the frame or the distance around the picture.

PERIMETER

Thus the total length or the distance around the picture is its perimeter.

Example: Find the perimeter of the following figure.

Sol: Perimeter = 4cm + 7cm + 6cm = 17cm

Example: Find the perimeter of the following figure. Take each square to have sides of 1cm.

(Count the number of shaded squares to get the perimeter.)

Sol: There are 18 squares that are shaded.

Therefore, Perimeter = 18cm

Example: Use a centimetre ruler to find the perimeter of the following figure.

Sol: (We can get the perimeter of the above given figure by measuring all its sides.)

Perimeter = Sum of the length of all sides.

=3cm+1cm+1cm+3cm+1cm+1cm+ 3cm+1cm+1cm+

3cm+1cm+1cm=20cm

Example: Find the missing length of the following figure.

Perimeter=20cm

Sol: Perimeter=20cm

Sum of the lengths of the four sides=4cm+1cm+3cm+5cm=13cm

Length of the missing (fifth) side= Perimeter - sum of the lengths of the four sides

=20cm-13cm

= 7cm

Example: How much wire does Ahmad need to fence this garden?

(Note: First we need to find the perimeter of this garden i.e, the total length around it.)

Sol: Perimeter of this garden =9m+12m+10m= 31m

Therefore, Ahmad needs 31m wire to fence the garden.

Example: How much distance did Rajesh cover if he has taken 5 rounds

around the playground?

around the playground?

Sol: perimeter of the playground= 7cm+5cm+7cm+5cm

= 24cm

No. of rounds taken =5

Distance covered in 1 round=24cm

Distance covered in 5 rounds=24×5=120cm

Therefore,Rajesh covered 120cm in 5 rounds.

Perimeter of a Rectangle:

Let us consider a rectangle with length=6cm and breadth=4cm.

4cm 6cm

Perimeter of Rectangle= 2 times (sum of length and breadth)

=2× (l+b)

= 2×(6am+ 4cm)

=2(6cm+ 4cm)

Perimeter of a Square:

Let us consider a square with sideis 3cm.

3cm 3cm

Perimeter of square= 4 times ( length of each side)

= 4×3cm

= 12cm.

Perimeter (Worksheet-1)

Q1. Find the perimeter of the given figures.

Q2. Find the perimeter of the given square cardboard.

Q3. Find the perimeter of the rectangle whose length is 20m and breadth is 15m.

Q4. The perimeter of a square is 408m. Find the length of each

side of a square.

CARD BOARD

6cm

3cm

5cm

4cm

2cm

Please click the link below to download CBSE Class 5 Mathematics-Area and Perimeter (1)