A triangular piece of land has a base of 390 meters and a height of 280 meters. What is the area of this land in hectares?
一块三角形土地，底是390米，高是280米．这块土地的面积是多少公顷．
<gadget id="calculator">280 / 2 / 10_000</gadget>
<output>7/500 = around 0.014</output>

<gadget id="calculator">390 * (7/500)</gadget>
<output>273/50 = around 5.46</output>

<result>273/50 = around 5.46</result>