After a bamboo pole with a total length of 5 meters is inserted into the water, the part above the water is 1.2 meters long. How deep is the water?
竹竿全长5米插入水中后，露出水面部分长1.2米，水深多少米？
<gadget id="calculator">5 - 1.2</gadget>
<output>3.8</output>

<result>3.8</result>