A cylindrical bucket, measured from the inside, has a base radius of 20 cm and a height of 50 cm. How many liters of water can this bucket hold?
一个圆柱形水桶，从里面量，底面半径是20厘米，高是50厘米．这个桶可装水多少升？
<gadget id="calculator">20 ** 2</gadget>
<output>400</output>

<gadget id="calculator">50 / 1_000</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">3.14 * 400 * (1/20)</gadget>
<output>62.8</output>

<result>62.8</result>