There is a trapezoidal mirror on the large wardrobe, the upper base is 1.5 decimeters, the lower base is 60 cm, and the height is 80 cm. What is the area of this mirror in square decimeters?
大衣柜上有一面梯形镜子，上底1.5分米，下底60厘米，高是80厘米．这面镜子的面积是多少平方分米？
<gadget id="calculator">60 / 10</gadget>
<output>6</output>

<gadget id="calculator">1.5 + 6</gadget>
<output>7.5</output>

<gadget id="calculator">80 / 10</gadget>
<output>8</output>

<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">7.5 * 4</gadget>
<output>30</output>

<result>30</result>