There is a cylindrical stake cut along the diameter, the section is a square, the circumference of the bottom of the cylinder is 12.56 decimeters, find the volume of the cylinder.
有一个圆柱形木桩，沿直径切开，截面是一个正方形，圆柱的底面周长是12.56分米，求圆柱的体积．
<gadget id="calculator">12.56 / 3.14</gadget>
<output>4</output>

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

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

<gadget id="calculator">3.14 * 4 * 4</gadget>
<output>50.24</output>

<result>50.24</result>