Avneet buys 9 square paving slabs, each with a side of 
m. He lays them in the form of a square.
(a) What is the perimeter of his arrangement [Fig. (i)]?
(b) Shari does not like his arrangement. She gets him to lay them out like a cross. What is the perimeter of her arrangement [Fig. (ii)]?
(c) Which has greater perimeter?
(d) Avneet wonders if there is a way of getting an even greater perimeter. Can you find a way of doing this? (The paving slabs must meet along complete edges, i.e., they cannot be broken)
(a) From the given figure, the side of one slab is 
m
Therefore, the side of square = (3 × 
) m = 
m
Now,
We know that the perimeter of a square = 4 × Side
= 4 × 
= 6 m
(b) We know that,
Perimeter = Sum of all sides
Therefore Perimeter = 0.5 + 1 + 1 + 0.5 + 1 + 1 + 0.5 + 1 + 1 + 0.5 + 1 + 1
= 10 m
(c) The arrangement which is in the shape of cross has a greater perimeter (i.e. 10 m)
(d) If we put all 9 slabs in a line then, the perimeter will be 10 m, as shown below.
Thus, from the given arrangements, arrangements with perimeters greater than 10 m cannot be determined.