canal is trapezoidal in cross section, 0.8 meters deep, 1.2 meters wide at the bottom, and 2 meters wide at the mouth. What is the cross-sectional area in square meters?
一条水渠横截面是梯形，渠深0.8米，渠底宽1.2米，渠口宽2米，横截面积是多少平方米？
<gadget id="calculator">1.2 + 2</gadget>
<output>3.2</output>

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

<gadget id="calculator">3.2 * 0.4</gadget>
<output>1.28</output>

<result>1.28</result>