The cross section of a canal is trapezoidal, the width of the canal mouth is 2.5m, the width of the canal bottom is 1.5m, and the canal is 2 meters deep. What is the area of the cross section of this canal in square meters?
一条水渠的横截面是梯形，渠口宽是2.5m，渠底宽是1.5米，渠深2米，这条水渠横截面的面积是多少平方米．
<gadget id="calculator">2.5 + 1.5</gadget>
<output>4</output>

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

<gadget id="calculator">4 * 1</gadget>
<output>4</output>

<result>4</result>