The perimeter of a rectangular test field is 240 meters. It is known that the ratio of length to width is 2:1. What is the area of this test field in hectares?
一块长方形试验田的周长是240米，已知长与宽的比是2：1，这块试验田的面积是多少公顷？
<gadget id="calculator">240 / 2</gadget>
<output>120</output>

<gadget id="calculator">1 + 2</gadget>
<output>3</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(2/3) / 10_000</gadget>
<output>1/15_000 = around 0.000067</output>

<gadget id="calculator">120 * (1/3) * 120 * (1/15_000)</gadget>
<output>8/25 = around 0.32</output>

<result>8/25 = around 0.32</result>