arc and rectangle cutaway in flange error message

[Kensound]

Hi. I'm working in sheet metal and have a flange and want to make a rectangle cutout where one side goes to the edge. I wasn't sure exactly how to do this but found while in sketch mode that I could draw 3 line segments starting and ending at the edge of the flange to make the rectangular shape, then use the trim tool to get rid of the line between the 2 endpoints to complete the task. When I exit sketch mode however I get errors saying the drawing is open and so on. However if I hit "ignore" I find the operation actually works and a "check part" operation shows no errors in the part and the cutout looks great. All this also happens if I make an arc cutout using the flange edge as the start and end points of the arc.

So my question is should I ignore this message and assume my drawing is fine? Also is there a better way to make an arc and rectangular cutaway?

Thanks.

 

[traffic_hazard]

It is interesting that it works. You really should close the loop in your sketch to clear the error. You can perform a cut operation where there is nothing to cut. Just connect the two points on the edge of the flange, or extend the lines past the edge and connect them. Nothing removed from nothing is still nothing.