Radius of roller = 84/2 cm = 42 cm Length of roller = 120 cm ∴ Curved surface area of roller = 2 πrh = 2 x 22/7 x 42 x 120 = 31680 cm2 As the roller takes 500 complete revolutions to level the playground ∴ Area of play ground = 500 x 31680 cm2 = 15840000 cm2 = 15840000/10000 m2 = 1584 m2