cylindrical stake is cut along the diameter, the section is a square, and the circumference of the bottom of the cylinder is 6.28 decimeters, find the volume of the cylinder.
一个圆柱形木桩，沿直径切开，截面是一个正方形，圆柱底面周长是6.28分米，求圆柱的体积．
<gadget id="calculator">6.28 / 3.14</gadget>
<output>2</output>

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

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

<gadget id="calculator">3.14 * 1 * 2</gadget>
<output>6.28</output>

<result>6.28</result>