Cut out a right-angled triangle whose side lengths are 3cm, 4cm, and 5cm from a trapezoidal cardboard with an upper base of 12cm, a lower base of 18cm, and a height of 8cm. What is the area of the remaining part in cm**2.
在一个上底为12cm、下底为18cm、高是8cm的梯形硬纸板中剪去一个边长分别为3cm、4cm、5cm的直角三角形，剩下部分的面积是多少cm**2．
<gadget id="calculator">12 + 18</gadget>
<output>30</output>

<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">30 * 4</gadget>
<output>120</output>

<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<gadget id="calculator">120 - 6</gadget>
<output>114</output>

<result>114</result>