The minute hand of a circular clock face is 10 cm long. From 1 o'clock to 1:30, what is the area swept by the minute hand in square centimeters?
一个圆形钟面的分针长10厘米，从1点整走到1点半，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>