A cube container with a side length of 20 cm is filled with water, and then a watermelon is gently submerged in the water, and then taken out. At this time, the height of the water surface is 11 cm. Find the volume of the watermelon. (excluding water loss)
一个棱长是20厘米的正方体容器里装满水，再将一个西瓜轻轻放入浸没在水中，然后取出，这时水面高度是11厘米，求这个西瓜的体积．(不计水损失)
<gadget id="calculator">20 - 11</gadget>
<output>9</output>

<gadget id="calculator">20 * 20 * 9</gadget>
<output>3_600</output>

<result>3_600</result>