The minute hand of a tower clock is 21 cm long. What area does the hand sweep out between 6:00 and 6:45? Take $\pi = \frac{22}{7}$.

Explanation

1. 01

   In 45 minutes the minute hand turns through $45/60$ = ¾ of a full turn, i.e. 270°.

2. 02

   Full circle = $\frac{22}{7} \times 21 \times 21 = 1386$ cm².

3. 03

   Swept area = $\tfrac{3}{4} \times 1{,}386 = 1{,}039.5$ cm².