The area of a trapezoid is 27cm**2, the sum of the upper and lower bases is 9cm, what is the height of the trapezoid in cm?
一个梯形的面积是27cm**2，上下底之和是9cm，这个梯形的高是多少cm．
<gadget id="calculator">2 / 9</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">27 * (2/9)</gadget>
<output>6</output>

<result>6</result>