The minute hand on a clock face is 5 cm long. What is the area in square centimeters that the minute hand sweeps after 1 hour?
某钟面上的分针长5厘米，经过1小时后，分针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</gadget>
<output>78.5</output>

<result>78.5</result>