Question

minute hand clock is 5 cm long. find the area of the sector formed by this hand in 7 minute

Answer 1

In 60 mins minute hand completes 360°
In 1 min minute hand will complete = 360/60 = 6°
In 7 mins minute hand will complete =6*7=42° =Ф
So area of sector =πr² x Ф/360
                            = 55/6 cm²

Answer 2

in 60 min ,minute hand completes degree =360
in 1 min ,minute hand will complete angle = 360/60=6 degree
angle made in 7 minute = 6×7=42 degree

as we know that.
360 degree covers area = pi r^2
1 degree will cover area = pi r^2/360
42 degree will cover area = (pi r^2/360)×42
22×25×42/(7×360)
55/6
9.16 sq cm