The sum of the upper and lower bases of a trapezoid is 15cm, the height is 8.8cm, what is the area in cm**2.
一个梯形上底与下底的和是15cm，高是8.8cm，面积是多少cm**2．
<gadget id="calculator">8.8 / 2</gadget>
<output>4.4</output>

<gadget id="calculator">15 * 4.4</gadget>
<output>66</output>

<result>66</result>