A trapezoid, the upper base is 9 cm, the lower base is 5 cm longer than the upper base, and the height is 4 cm shorter than the lower base, what is the area of the trapezoid in square centimeters?
一个梯形，上底是9厘米，下底比上底长5厘米，高比下底短4厘米，这个梯形的面积是多少平方厘米．
<gadget id="calculator">9 + 5</gadget>
<output>14</output>

<gadget id="calculator">9 + 14</gadget>
<output>23</output>

<gadget id="calculator">14 - 4</gadget>
<output>10</output>

<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">23 * 5</gadget>
<output>115</output>

<result>115</result>