The minute hand of a wall clock is 10 cm long. After 0.5 hours, what is the area swept by the minute hand in square centimeters?
一只挂钟的分针长10厘米，经过0.5小时后，分针扫过的面积是多少平方厘米．
<gadget id="calculator">10 ** 2</gadget>
<output>100</output>

<gadget id="calculator">100 / 2</gadget>
<output>50</output>

<gadget id="calculator">3.14 * 50</gadget>
<output>157</output>

<result>157</result>