The upper base of a trapezoid is 3.5 cm, the lower base is 4.5 cm, and the height is 2 cm. What is the area of the trapezoid in square centimeters?
一个梯形的上底是3.5cm，下底是4.5cm，高是2cm，这个梯形的面积是多少平方厘米．
<gadget id="calculator">3.5 + 4.5</gadget>
<output>8</output>

<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">8 * 1</gadget>
<output>8</output>

<result>8</result>