If a cylinder with a height of 20 cm is cut into two sections, the surface area increases by 50.24 square centimeters. What is the original volume of the cylinder?
把高为20厘米的圆柱体横截成两段，表面积增加了50.24平方厘米，这个圆柱体的原来体积是多少．
<gadget id="calculator">50.24 / 2</gadget>
<output>25.12</output>

<gadget id="calculator">25.12 * 20</gadget>
<output>502.4</output>

<result>502.4</result>