After reducing one pair of opposite sides of a square by 12 cm and 8 cm respectively, a trapezoid is obtained. The length of one base of this trapezoid is 5 times that of the other base. What is the area of the trapezoid in square centimeters?
把一个正方形的其中一组对边分别减少12厘米和8厘米后，就得到一个梯形，这个梯形的一个底的长度是另一个底的5倍，求梯形的面积是多少平方厘米？
<gadget id="calculator">5 * 12</gadget>
<output>60</output>

<gadget id="calculator">60 - 8</gadget>
<output>52</output>

<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">52 / 4</gadget>
<output>13</output>

<gadget id="calculator">13 - 12</gadget>
<output>1</output>

<gadget id="calculator">13 - 8</gadget>
<output>5</output>

<gadget id="calculator">1 + 5</gadget>
<output>6</output>

<gadget id="calculator">52 / 4 / 2</gadget>
<output>13/2 = around 6.5</output>

<gadget id="calculator">6 * (13/2)</gadget>
<output>39</output>

<result>39</result>