Cut a cylinder into several equal small sectors from the bottom and assemble it into an approximate cuboid with a height of 10 cm and a width of 5 cm. What is the volume of the original cylinder in cubic centimeters?
把一个圆柱，从底面切成若干个相等的小扇形，拼成一个近似的长方体，高是10厘米，宽是5厘米，原来圆柱的体积是多少立方厘米．
<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

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

<result>785</result>