The hour hand of a clock is 5 cm long. How many square centimeters does the hour hand sweep in one day?
一只钟表的时针长5厘米，一天下来时针所扫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>