Cut a cuboid block with base length 5 cm and height 20 cm into the largest cylinder. What is the volume of this cylinder in cubic centimeters?
将一个底面边长为5厘米，高20厘米的长方体木块，削成一个最大的圆柱，这个圆柱的体积是多少立方厘米．
<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">(5/2) ** 2</gadget>
<output>25/4 = around 6.25</output>

<gadget id="calculator">3.14 * (25/4) * 20</gadget>
<output>392.5</output>

<result>392.5</result>