If the diameter and height of the base of a log are both 4 decimeters, what is the volume of the cylinder in cubic decimeters?
一根圆木底面的直径和高都是4分米，这个圆柱体的体积是多少立方分米．
<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>