A trapezoidal test field, the bottom is 18m long, and the top and height are 3.6m. How many square meters does this test field occupy?
一块梯形试验田，下底长18m，上底和高都是3.6m，这块试验田占地多少平方米？
<gadget id="calculator">18 + 3.6</gadget>
<output>21.6</output>

<gadget id="calculator">3.6 / 2</gadget>
<output>1.8</output>

<gadget id="calculator">21.6 * 1.8</gadget>
<output>38.88</output>

<result>38.88</result>