There is a trapezoidal iron plate, the upper base is 1.8 meters, the lower base is 3.2 meters, and the height is as long as the upper base. What is the area of this iron plate?
有一块梯形铁板，上底1.8米，下底3.2米，高与上底同样长，这块铁板的面积是多少？
<gadget id="calculator">1.8 + 3.2</gadget>
<output>5</output>

<gadget id="calculator">1.8 / 2</gadget>
<output>0.9</output>

<gadget id="calculator">5 * 0.9</gadget>
<output>4.5</output>

<result>4.5</result>