A canal has been built for 1,200 kilometers. At this time, the ratio of the ones that have been built to the ones that have not been built is 3:2. How many kilometers is the total length of this canal? (Solution with proportional knowledge)
修一条水渠，已修1200千米，这时已修的和未修的比是3：2，这条水渠全长多少千米？(用比例知识解)
<gadget id="calculator">3 / 2</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">(3/2) * 1_200</gadget>
<output>1_800</output>

<gadget id="calculator">1_200 + 1_800</gadget>
<output>3_000</output>

<gadget id="calculator">3_000 / (3/2)</gadget>
<output>2_000</output>

<result>2_000</result>