The area of a trapezoid is 70 square centimeters, its lower base is 8 cm, and its height is 10 cm. What is its upper base?
一个梯形的面积是70平方厘米，它的下底是8厘米，高是10厘米，它的上底是多少．
<gadget id="calculator">2 / 10</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">70 * (1/5)</gadget>
<output>14</output>

<gadget id="calculator">14 - 8</gadget>
<output>6</output>

<result>6</result>