The upper base of a trapezoid is 1.2 meters, the lower base is 3.8 meters, its area is 20.5 square meters, what is its height?
一个梯形的上底是1.2米，下底是3.8米，它的面积是20.5平方米，它的高是多少．
<gadget id="calculator">1.2 + 3.8</gadget>
<output>5</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">20.5 * (2/5)</gadget>
<output>8.2</output>

<result>8.2</result>