Question

The length of a roller is 40cm.and its diametre is 21cm.it takes 300complete revolution to move once over to level the floor of a room.find the area of room in metre square

Answer 1

area of rollar is h×2pie r   =40×2×22/7×21/2  =40×22×3  =2640cm^2  area of floor= area of roller and times  he moves= 2640×300cm  = 792000cm^2  =  7920m^2  #hope it helps #mark as brainliest