An approximately trapezoidal pool has an area of 13.14 square meters, an upper bottom of 4.8 meters and a height of 2.5 meters. How many meters is the lower bottom?
一个近似梯形的水池面积是13.14平方米，上底4.8米，高2.5米，下底多少米？
<gadget id="calculator">2 / 2.5</gadget>
<output>0.8</output>

<gadget id="calculator">13.14 * 0.8</gadget>
<output>10.512</output>

<gadget id="calculator">10.512 - 4.8</gadget>
<output>5.712</output>

<result>5.712</result>