The area of a trapezoid is 45cm**3, the length of the upper base is 5cm, the height is 6cm, and the length of the lower base is cm.
一个梯形的面积是45cm**3，上底长5cm，高是6cm，下底长多少cm．
<gadget id="calculator">2 / 6</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">45 * (1/3)</gadget>
<output>15</output>

<gadget id="calculator">15 - 5</gadget>
<output>10</output>

<result>10</result>