The sum of the two bases of a trapezoid is 12 cm and the height is 14 cm. What is the area in square centimeters?
一个梯形两个底的和是12厘米，高是14厘米，面积是多少平方厘米？
<gadget id="calculator">14 / 2</gadget>
<output>7</output>

<gadget id="calculator">12 * 7</gadget>
<output>84</output>

<result>84</result>