The minute hand of a clock is 5 cm long. What is the area swept by the minute hand of this clock from 12 o'clock to 6 o'clock?
一个钟表的分针长5cm，这个钟表从12时走到6时，分针扫过的面积是多少．
<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">12 - 6</gadget>
<output>6</output>

<gadget id="calculator">3.14 * 25 * 6</gadget>
<output>471</output>

<result>471</result>