The area of a trapezoid is 3.12 square meters, the upper base is 2.5 meters, and the lower base is 1.4 meters. What is the height in meters?
一个梯形面积是3.12平方米，上底2.5米，下底1.4米，高是多少米．
<gadget id="calculator">2.5 + 1.4</gadget>
<output>3.9</output>

<gadget id="calculator">2 / 3.9</gadget>
<output>0.512821</output>

<gadget id="calculator">3.12 * 0.512821</gadget>
<output>1.600002</output>

<result>1.600002</result>