Cut a cylinder with a height of 1 decimeter into many equal sectors at the bottom, and then assemble it into an approximate cuboid. The surface area of the cuboid increases by 40 square centimeters. Find the volume of the original cylinder?
把一个高为1分米的圆柱体切成底面是许多相等的扇形，再拼成一个近似的长方体，长方体的表面积增加了40平方厘米，求原来柱体体积？
<gadget id="calculator">1 * 10</gadget>
<output>10</output>

<gadget id="calculator">40 / 2 / 10</gadget>
<output>2</output>

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

<gadget id="calculator">3.14 * 4 * 10</gadget>
<output>125.6</output>

<result>125.6</result>