The base of a parallelogram is 24 cm, and the height of the base is 8 cm. If one of the bases is reduced by 6 cm, it becomes a trapezoid. What is the area of the trapezoid in square centimeters?
一个平行四边形的底为24厘米，该底边上的高为8厘米，将其中一条底减少6厘米后变成了一个梯形，这个梯形的面积是多少平方厘米．
<gadget id="calculator">24 - 6</gadget>
<output>18</output>

<gadget id="calculator">24 + 18</gadget>
<output>42</output>

<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">42 * 4</gadget>
<output>168</output>

<result>168</result>