The upper base of a trapezoid is 6 cm long. If the upper base is extended by 4 cm to form a square, what is the area of the trapezoid in square centimeters?
一个梯形的上底长6厘米，如果把上底延长4厘米就成了一个正方形，这个梯形的面积是多少平方厘米．
<gadget id="calculator">6 + 4</gadget>
<output>10</output>

<gadget id="calculator">6 + 10</gadget>
<output>16</output>

<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">16 * 5</gadget>
<output>80</output>

<result>80</result>