The cross section of a canal is trapezoidal, the width of the mouth is 1.8m, the depth of the canal is 0.8m, and the width of the bottom of the canal is 1.2m. What is the area of the cross section in square meters?
一条水渠横截面是梯形，渠口宽1.8m，渠深0.8m，渠底宽1.2m，横截面的面积是多少平方米？
<gadget id="calculator">1.2 + 1.8</gadget>
<output>3</output>

<gadget id="calculator">0.8 / 2</gadget>
<output>0.4</output>

<gadget id="calculator">3 * 0.4</gadget>
<output>1.2</output>

<result>1.2</result>