The upper base of a trapezoid is the lower base (2/3), and the upper base is extended by 4 cm to form a parallelogram with an area of 108 cm**2. What is the area of the trapezoid in cm**2?
一个梯形上底是下底的(2/3)，把上底延长4cm，就成了一个平行四边形，面积是108cm**2，梯形的面积是多少cm**2．
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 - (2/3)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">4 / (1/3)</gadget>
<output>12</output>

<gadget id="calculator">12 * (2/3)</gadget>
<output>8</output>

<gadget id="calculator">12 + 8</gadget>
<output>20</output>

<gadget id="calculator">108 / 12</gadget>
<output>9</output>

<gadget id="calculator">9 / 2</gadget>
<output>9/2 = around 4.5</output>

<gadget id="calculator">20 * (9/2)</gadget>
<output>90</output>

<result>90</result>