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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def re_rect(FlowRate, Width, DistCenter, Nu, openchannel):
 """Return the Reynolds Number for a rectangular channel."""

    #Checking input validity - inputs not checked here are checked by
    #functions this function calls.
    ut.check_range([FlowRate, ">0", "Flow rate"], [Nu, ">0", "Nu"])
    return (4 * FlowRate
            * radius_hydraulic(Width, DistCenter, openchannel).magnitude
            / (Width * DistCenter * Nu))