A cylindrical piece of wood is cut into four parts with the diameter of the bottom surface along the height, and the surface area is increased by 800 square centimeters. What is the volume of a piece of wood whose base has a radius of 5 cm?
把一根圆柱形的木料通成底面直径沿高切成相同的四份，表面积增加了800平方厘米．圆柱的底面半径5厘米这根木料的体积是多少．
<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">800 / 4</gadget>
<output>200</output>

<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<gadget id="calculator">200 / 10</gadget>
<output>20</output>

<gadget id="calculator">3.14 * 25 * 20</gadget>
<output>1_570</output>

<result>1_570</result>