A piece of cardboard is a right triangle, the lengths of the two sides are 3 cm and 4 cm respectively, if it is rotated around the longer side as the axis, what is the volume of the cone formed?
一张直角三角形的硬纸片，两边直角边长分别为3厘米和4厘米，如果以较长的直角边为轴将它旋转一周，形成的圆锥的体积是多少．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

<gadget id="calculator">(1/3) * 3.14 * 9 * 4</gadget>
<output>37.68</output>

<result>37.68</result>