A piece of conical metal with a bottom diameter of 40cm is put into a cylindrical glass with a bottom diameter of 80cm. The water level in the glass rises by 3cm. What is the height of this piece of metal?
把一块底面直径为40cm的圆锥形金属，投入底面直径为80cm的圆柱形玻璃杯中，杯中水面升高3cm，这块金属的高是多少？
<gadget id="calculator">80 / 2</gadget>
<output>40</output>

<gadget id="calculator">40 ** 2</gadget>
<output>1_600</output>

<gadget id="calculator">3.14 * 1_600</gadget>
<output>5_024</output>

<gadget id="calculator">5_024 * 3</gadget>
<output>15_072</output>

<gadget id="calculator">40 / 2</gadget>
<output>20</output>

<gadget id="calculator">20 ** 2</gadget>
<output>400</output>

<gadget id="calculator">3.14 * 400</gadget>
<output>1_256</output>

<gadget id="calculator">3 / 1_256</gadget>
<output>3/1_256 = around 0.002389</output>

<gadget id="calculator">15_072 * (3/1_256)</gadget>
<output>36</output>

<result>36</result>