A cistern is 5 meters long, 4 meters wide, and 2.5 meters high. How many square meters does this pool occupy?
一个蓄水池，长5米，宽4米，高2.5米，这个水池的占地面积是多少平方米？
<gadget id="calculator">5 * 4</gadget>
<output>20</output>

<result>20</result>