A teepee has a base radius of 3m and a height of 2m. How much space does it have inside?
一个圆锥形帐篷，它的底面半径是3m，高是2m，它的里面空间有多少．
<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">3.14 * 9</gadget>
<output>28.26</output>

<gadget id="calculator">(1/3) * 28.26 * 2</gadget>
<output>18.84</output>

<result>18.84</result>