cylindrical oil barrel, the radius of its inner bottom surface is 20 decimeters, and the height is 50 decimeters, how many liters of gasoline can this oil barrel hold at most?
一个圆柱形的油桶，它内部的底面半径是20分米，高为50分米，这只油桶最多可以装汽油多少升？
<gadget id="calculator">20 ** 2</gadget>
<output>400</output>

<gadget id="calculator">3.14 * 400 * 50</gadget>
<output>62_800</output>

<result>62_800</result>