Math, asked by dtnikam9014, 1 year ago

The length of a roller is 40 cm and its diameter is 21 cm It takes 300 complete revolutions to move once over to level a floor of a room find the area of the room in metres square

Answers

Answered by aseerahmadwani
11
length of roller "h"=40cm=4/10m
Diameter " " d =21cm= 21/100m
therefore Radius r=21/200m
in one revolution
Area level by roller = Curve S-A of roller
= 2πrh
put values of π r and h
you will get area level in 1 revolution and multiple this by300 you will get total area of room
Answered by triptekade
8

area \:  = 300 \times 2\pi \: rh \\  = 300 \times 2 \times 3.14 \times (21 \div 2) \times 40 \\  = 1884 \times 10.5 \times 40 \\  = 791280cm {}^{2}  \\  = 79.1280 \: m {}^{2}
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