There is a newly dug canal, the cross section is trapezoidal, its area is 2.52 square meters, the mouth of the canal is 2.8 meters wide, and the bottom of the canal is 1.4 meters wide. How deep is the canal? (solution by equation)
有一个新挖的渠道，横截面是梯形，它的面积是2.52平方米，渠口宽2.8米，渠底宽1.4米，渠深多少米？(用方程解)
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">2.8 * (1/2)</gadget>
<output>1.4</output>

<gadget id="calculator">1.4 * (1/2)</gadget>
<output>0.7</output>

<gadget id="calculator">1.4 + 0.7</gadget>
<output>2.1</output>

<gadget id="calculator">2.52 / 2.1</gadget>
<output>1.2</output>

<result>1.2</result>