An approximately conical sand pile with a base radius of 3 meters and a height of 2 meters. Calculated at 0.5 cubic meters per ton of sand, how many tons does this pile of sand weigh?
一个近似圆锥形沙堆，底面半径3米，高2米．按每吨沙0.5立方米计算，这堆沙重多少吨？
<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">2 / 0.5</gadget>
<output>4</output>

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

<result>37.68</result>