Based on CHAPTERs10. Visualizing Solid shapes11. Mensuration5. Data Handling15. Introduction to Graphs

Class 08 Activity – Volumes and Surface Areas

Objective: 

To explore the relationship between

(i)  length (in cm ) and perimeter (in cm)

(ii) length (in cm) and area (in cm²) 

Of 5 squares of different dimensions drawn on a squared paper.

Materials Required:  

Squared paper, colour pencils, geometry box,  etc.

Procedure 

On a squared paper, draw five squares of different dimensions. Name these squares as1 2 3 4 5. 

Now, measure the perimeter of each square. Also, count the number of small squares (the area of each small square being 1 cm²) enclosed by each square to get their areas. 

Complete the following table.

Observations:

 From the table, we observe that:

Perimeter of a square is four times its length. Or side of a square is one fourth of its perimeter. 

So, for а square,  "Perimeter" /"Length" =4. 

2. Area of a square of length l is l x l = l ². Or side of a square of area A square units is √A units.

 So, for a square, "Area" /"Length" = Length

Conclusion: 

From the above activity, we observe that for a square of length l :

Perimeter = 4 x l 

2. Area = l x l = l ² 

Do Yourself: On a squared paper, draw four different squares and explore the relationship between:

1. length and perimeter

2. length and area.