The minute hand of a clock is 15cm long. Calculate the area swept by it in 20 minutes. [Take `pi=3.14`]

Answer

`235.5cm^(2)`

Explanation

Angle described by the minute hand in 20 minutes `=(360/60xx20)^(@)=120^(@)`
Now `theta=120^(@)` and `r=15cm`
`:.` area swept by minute hand in 20 min `=((pir^(2)theta)/360)cm^(2)`
`=(3.14xx15xx15xx120/360)cm^(2)`
`=235.5cm^(2)`