The diameter of a roller is 84 cm and its length is 120 cm. It takes 500 complete revolutions to move once over to level a playground. Find the area of the playground in m².

Radius of roller r = 84/2 = 42 cm = 0.42 m and length h = 120 cm = 1.2 m
outer curved surface area of roller = 2πrh
= 2 × 22/7 × 0.42 × 1.2 = 2 × 22 × 0.06 × 1.2 = 3.168 m²
Area of ground levelled in on revolution = 3.168 m²
Therefore, area of ground levelled in 500 revolutions = 500 × 3.168 = 1584 m²
Hence, the area of playground is 1584 m².