A rectangular fish farm with an area of 6 hectares has a width of 200 meters and a length of 200 meters.
面积为6公顷的长方形鱼场，宽是200米，长是多少米．
<gadget id="calculator">6 * 10_000</gadget>
<output>60_000</output>

<gadget id="calculator">60_000 / 200</gadget>
<output>300</output>

<result>300</result>