the lenght of a minute hand of a wall clock is 7cm.How much area does it sweep in 20 minutes?
In 60 min, the minute hand sweeps 360 degrees.
Hence in 20 min, the minute hand sweeps 20*360/60 = 120 degrees.
The area swept will be the area of the sector formed by the minute hand.
Therefore, Area swept = Area of sector
= theta / 360 * pi radius2
= 120 / 360 * 22/7 * 72
= 154 / 3
= 51.33 cm2
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