A cylindrical wooden barrel with a bottom diameter of 20 cm is filled with water, and an iron cone with a bottom diameter of 18 cm and a height of 20 cm is submerged in the water. How much will the water level in the bucket be lowered when the cone is removed?
一个底面直径为20厘米的圆柱形木桶里装有水，水中淹没着一个底面直径为18厘米、高为20厘米的铁质圆锥体．当圆锥体取出后，桶内水面将降低多少？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">18 / 2</gadget>
<output>9</output>

<gadget id="calculator">9 ** 2</gadget>
<output>81</output>

<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">20 / 314</gadget>
<output>10/157 = around 0.063694</output>

<gadget id="calculator">(1/3) * 3.14 * 81 * (10/157)</gadget>
<output>5.4</output>

<result>5.4</result>