Question

a road roller takes 750 complete revolutions to move once over to level a road find the area of the road if the diameter of a road roller is 84cm and length is 1m

Answer 1

diameter of road roller = 84 cm
radius of road roller = 84/2 cm= 42 cm = 0.42 m
length of road roller = 1m
area of road roller = 2×pi×radius×height
= 2×(22/7)×0.42×1 m^2
[Note : Length can be taken as height as the cylindrical roller is not standing upright]
= 2×22×0.06×1 m^2
= 44×0.06 cm^2
= 2.64 m^2
Now area of road = 2.64 m^2 × 750
= 1980 cm^2
Hence area of road = 1980 m^2 or 198000 cm^2

Answer 2

Length of roller = 1m = 100cm

Circumference of roller = π x D = 22/7 X 84 =  264 cm

Length of road = 264 x 750 = 198000 cm

Width of road = length of roller = 100 cm

Area of road = 198000 x 100 = 19,800,000 cm² or 1980 m²

hope it helps!!