A right-angled trapezoid, if the upper base is extended by 6 cm, the area increases by 60 cm2 and becomes a square, what is the area of the original trapezoid in cm2?
一个直角梯形，如果把上底延长6厘米，面积就增加了60平方厘米，并且变成了一个正方形，原来梯形的面积是多少平方厘米．
<gadget id="calculator">2 / 6</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">60 * (1/3)</gadget>
<output>20</output>

<gadget id="calculator">20 * 20</gadget>
<output>400</output>

<gadget id="calculator">400 - 60</gadget>
<output>340</output>

<result>340</result>