A cuboid steel plate with a length of 47.1m, a width of 20m and a height of 10m is cast into a cylindrical steel column with a bottom diameter of 20m. How high is the cylindrical steel column?
一块长47.1m、宽20m、高10m的长方体钢板，铸造成底面直径为20m的圆柱形钢柱，圆柱形钢柱有多高？
<gadget id="calculator">20 / 2</gadget>
<output>10</output>

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

<gadget id="calculator">3.14 * 100</gadget>
<output>314</output>

<gadget id="calculator">10 / 314</gadget>
<output>5/157 = around 0.031847</output>

<gadget id="calculator">47.1 * 20 * (5/157)</gadget>
<output>30</output>

<result>30</result>