Expand a cylinder sideways to obtain a rectangle with a length of 31.4 cm and a width of 10 cm. What is the volume of this cylinder in cubic centimeters?
把一个圆柱侧面展开，得到一个长31.4厘米，宽10厘米的长方形，这个圆柱的体积是多少立方厘米．
<gadget id="calculator">31.4 / 3.14 / 2</gadget>
<output>5</output>

<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">3.14 * 25 * 10</gadget>
<output>785</output>

<result>785</result>