A trapezoid with a lower base of 8 cm long becomes a square if the lower base is reduced by 2 cm. What is the area of the trapezoid in square centimeters?
一个梯形，下底长8厘米，如果下底减少2厘米，就变成了正方形．原来这个梯形的面积是多少平方厘米．
<gadget id="calculator">8 - 2</gadget>
<output>6</output>

<gadget id="calculator">6 + 8</gadget>
<output>14</output>

<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">14 * 3</gadget>
<output>42</output>

<result>42</result>