trapezoid, if the upper base is extended by 8cm, becomes a parallelogram, and the area increases by 16cm**2, if the upper base of the original trapezoid is 4cm, what is the area of the original trapezoid in square centimeters?
一个梯形，如果上底延长8cm，就变成了一个平行四边形，而且面积增加了16cm**2，如果原来的梯形上底是4cm，原来梯形的面积是多少平方厘米？
<gadget id="calculator">2 / 8</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">16 * (1/4)</gadget>
<output>4</output>

<gadget id="calculator">4 + 8 + 4</gadget>
<output>16</output>

<gadget id="calculator">2 / 8 / 2</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">16 * 16 * (1/8)</gadget>
<output>32</output>

<result>32</result>