A cone with a height of 10 cm is cut in half from the apex of the cone along the height, and the surface area increases by 20 cm2 compared to the original. Find the volume of the cone.
一个圆锥的高是10厘米，从圆锥的顶点沿着高把它切成两半，表面积比原来增加了20平方厘米，求这个圆锥的体积．
<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">2 / 10</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">10 * (1/5)</gadget>
<output>2</output>

<gadget id="calculator">2 / 2</gadget>
<output>1</output>

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

<gadget id="calculator">(1/3) * 3.14 * 1 * 10</gadget>
<output>10.466667</output>

<result>10.466667</result>