The hour hand of a clock is 5 cm long, how many square centimeters does the tip of the hour hand cover in one day and night?
一个时钟的时针长5厘米，这个时针的尖端一昼夜走过的面积是多少平方厘米？
<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">3.14 * 25 * 2</gadget>
<output>157</output>

<result>157</result>