Cut a cylinder whose base circumference is 12.56 cm along the radius of the base into several equal parts and assemble it into a cuboid. The surface area is increased by 20 square centimeters compared to the original one. What is the volume of the original cylinder?
将一个底面周长是12.56厘米的圆柱沿底面半径切成若干等份拼成一个长方体，表面积比原来增加了20平方厘米，原来圆柱的体积是多少．
<gadget id="calculator">12.56 / 3.14 / 2</gadget>
<output>2</output>

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

<gadget id="calculator">20 / 2 / 2</gadget>
<output>5</output>

<gadget id="calculator">3.14 * 4 * 5</gadget>
<output>62.8</output>

<result>62.8</result>