trapezoid has an upper base of 6 cm in length and a lower base of 10 cm in height. What is the area of the trapezoid in square centimeters?
一个梯形，上底长6厘米，下底和高都是10厘米，这个梯形的面积是多少平方厘米．
<gadget id="calculator">6 + 10</gadget>
<output>16</output>

<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">16 * 5</gadget>
<output>80</output>

<result>80</result>