During a rainfall, Xiao Ming uses a 60 mm high conical container to measure the rainfall. If the container is just filled with rainwater when the rain stops, how many millimeters does the rainfall measure?
在一次降雨过程中，小明用一个高60毫米的圆锥形容器测降雨量，如果雨停时容器刚好接满雨水，则降雨量为多少毫米
<gadget id="calculator">60 / 3</gadget>
<output>20</output>

<result>20</result>