The circumference of the base of a cone is 12.56 decimeters and the height is 3 decimeters. What is its volume in cubic decimeters?
一个圆锥的底面积周长是12.56分米，高3分米，它的体积是多少立方分米．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">12.56 / 3.14 / 2</gadget>
<output>2</output>

<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">(1/3) * 3.14 * 4 * 3</gadget>
<output>12.56</output>

<result>12.56</result>