The factory needs to use cylindrical steel with a diameter of 10 cm to build a conical part blank with a diameter of 20 cm and a height of 9 cm. Q: How long does the cylindrical steel need to be cut?
工厂要用直径是10厘米圆柱形钢材建造一个直径是20厘米，高9厘米的圆锥形零件毛胚，问：需要截取多长的圆柱形钢材？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<gadget id="calculator">10 ** 2</gadget>
<output>100</output>

<gadget id="calculator">(1/3) * 3.14 * 100 * 9</gadget>
<output>942</output>

<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">3.14 * 25</gadget>
<output>78.5</output>

<gadget id="calculator">942 / 78.5</gadget>
<output>12</output>

<result>12</result>