If a cylinder with a base radius of 2 decimeters is cut along the height and radius and assembled into an approximate cuboid, the surface area increases by 16 square decimeters. What is the volume of this cylinder in cubic decimeters?
把一个底面半径是2分米的圆柱，沿高和半径切开然后拼成一个近似长方体，表面积增加了16平方分米，这个圆柱体的体积是多少立方分米．
<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">16 / 2 / 2</gadget>
<output>4</output>

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

<result>50.24</result>