Avneet buys 9 square paving slabs, each with a side of `1/2` m. He lays them in the form of a square. (a) What is the perimeter of his arrangement [Fig 10.7(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 10.7 (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.)

Explanation

(a)Side of square =` 3 xx`side= `3 xx 1 / 2`= 3 / 2 m
Perimeter of Square = `4 xx 3 / 2`=` 2 xx 3`= 6 m

(b) Perimeter = 0.5 +1+1+0.5 + 1 + 1 + 0.5 + 1 + 1 + 0.5 + 1 + 1= 10 m
(c) The arrangement given in theform of cross has greaterperimeter
(d) No, but we can achieve the same perimeter as Shari's arrangement by arranging all the squares in a row