A trapezoid has an upper base of 3.4 cm, a lower base of 4.6 cm, and a height of 2.7 cm. What is the area of the trapezoid?
一个梯形，上底是3.4厘米，下底是4.6厘米，高是2.7厘米，则这个梯形的面积是多少．
<gadget id="calculator">3.4 + 4.6</gadget>
<output>8</output>

<gadget id="calculator">2.7 / 2</gadget>
<output>1.35</output>

<gadget id="calculator">8 * 1.35</gadget>
<output>10.8</output>

<result>10.8</result>