A square paving brick has an area of 225cm^2. If each brick fits tightly in place, how many bricks are needed to pave a path 1.2m by 12m?

Question

Please show your working out :) thank youu.

Answer 1

We have a square paving brick with area 225 cm²

For side length s of a square with area A:  A = s² ... s = √A

That means each side is √225 = 15 cm

 

For the width:  1.2m(100 cm/m) = 120 cm

120/15 = 8 bricks wide

 

For the length:  12m(100 cm/m) = 1200 cm

1200 cm/15 cm = 80 bricks long

 

So we have 80 rows of 8 = 640 bricks