In a set of opposite sides of a square, one side is increased by 17 cm and the other side is decreased by 11 cm, thus becoming a trapezoid. The lower base of this trapezoid is 5 times longer than the upper base, what is the area of the trapezoid?
正方形的一组对边中，一条边增加17厘米，另一条边减少11厘米，这样就变成了梯形．这个梯形的下底的长是上底的5倍，梯形的面积是多少？
<gadget id="calculator">18 - 11</gadget>
<output>7</output>

<gadget id="calculator">7 + 18 + 17</gadget>
<output>42</output>

<gadget id="calculator">18 / 2</gadget>
<output>9</output>

<gadget id="calculator">42 * 9</gadget>
<output>378</output>

<result>378</result>