A right-angled trapezoid, if the lower base is reduced by 5cm, the trapezoid becomes a square with a side length of 7cm, what is the area of the trapezoid in cm**2.
一个直角梯形，如果把下底减少5cm，这个梯形就变成一个边长7cm的正方形，这个梯形的面积是多少cm**2．
<gadget id="calculator">5 + 7</gadget>
<output>12</output>

<gadget id="calculator">7 + 12</gadget>
<output>19</output>

<gadget id="calculator">7 / 2</gadget>
<output>7/2 = around 3.5</output>

<gadget id="calculator">19 * (7/2)</gadget>
<output>133/2 = around 66.5</output>

<result>133/2 = around 66.5</result>