If the sides of a cylindrical iron tank with a base radius of 5 cm are stretched along the height, it is exactly a square. What is the volume of the iron tank in cubic decimeters?
把一个底面半径为5厘米的圆柱形铁罐的侧面沿高展开后，正好是一个正方形，这个铁罐的体积是多少立方分米？
<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">5 / 1_000</gadget>
<output>1/200 = around 0.005</output>

<gadget id="calculator">3.14 * 25 * 2 * 3.14 * (1/200)</gadget>
<output>2.4649</output>

<result>2.4649</result>