Cut a cylinder into a cuboid, the surface area is increased by 20 square decimeters, the height of the cylinder is 1 meter, and the volume of the cylinder is cubic meters.
把一个圆柱切拼成一个长方体，表面积增加20平方分米，已知圆柱的高是1米，圆柱的体积是多少立方米．
<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

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

<result>3.14</result>