Reclaim a triangular piece of wasteland with a bottom length of 120 meters and a height of 80 meters. After all the land has been reclaimed, how many hectares have been reclaimed?
开垦一块三角形荒地，底长120米，高80米，全部开垦完，共开垦了多少公顷？
<gadget id="calculator">80 / 2</gadget>
<output>40</output>

<gadget id="calculator">120 * 40</gadget>
<output>4_800</output>

<gadget id="calculator">4_800 / 10_000</gadget>
<output>12/25 = around 0.48</output>

<result>12/25 = around 0.48</result>