What is the volume of the base of a cone with a circumference of 6.28 decimeters and a height of 3 decimeters?
圆锥底面周长6.28分米，高3分米，体积是多少．
<gadget id="calculator">6.28 / 3.14 / 2</gadget>
<output>1</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

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

<result>3.14</result>