A cone is cut along the diameter of the apex and the base, and the surface area increases by 30 square centimeters. If the height of the cone is 15 centimeters, what is the volume of the cone in cubic centimeters?
将一个圆锥体沿顶点和底面直径切开，表面积增加了30平方厘米，如果圆锥的高是15厘米，那么圆锥的体积是多少立方厘米．
<gadget id="calculator">30 / 2</gadget>
<output>15</output>

<gadget id="calculator">2 / 15</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">15 * (2/15)</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</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">3.14 * 1 * 15 * (1/3)</gadget>
<output>15.7</output>

<result>15.7</result>