The area of a trapezoid is 96 square centimeters, its lower base is 18 cm, and its height is 8 cm. How many centimeters is its upper base?
一个梯形的面积是96平方厘米，它下底是18厘米，高是8厘米，它的上底是多少厘米？
<gadget id="calculator">2 / 8</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">96 * (1/4)</gadget>
<output>24</output>

<gadget id="calculator">24 - 18</gadget>
<output>6</output>

<result>6</result>