Question

The minute hand of a clock is 10 cm long. Find the area of the face of the clock described by the minute hand between 8 :00am and 8: 25am
A) 130.8 cm²
B) 1570cm²
C) 157cm²
D) None of these​

Answer 1

Answer:

Angle described by the minute hand in 1 minute = 6° (Since in 60 minutes, the angle described is 360°)

Angle described by the minute hand in 25 minutes = 25×6° = 150°

Area swept by the minute hand in 25 minutes =

$\frac{θ}{360} \times \pi \: {r}^{2}$

⇒ Area swept by the minute hand in 25 minutes =

$\frac{150}{360} \times \pi \: {r}^{2} \\ = 130.95$

⇒ Area swept by the minute hand in 25 minutes = 130.95 cm^2