Lining up a new sketch precisely with an existing shape

[atdNMH7S]

I'm working with a box-type object and am cutting out areas on various panels. I'm trying to do an extrusion on one panel, but am having a hard time getting it to line up precisely with the existing panel. I'm doing the following:

-- Click on existing panel, create a sketch, create a 2-point rectangle

-- Click on one corner of the existing panel to start the new rectangle there, then drag out to create the new rectangle

-- Do an extrusion with "cut" selected as the operation in order to cut out the defined portion of the existing panel

No matter how carefully I select the starting point for the new sketch, I always seem to be a bit off, and a sliver of unwanted material remains after I do the extrusion.

Do I need to enable something like a "snap to feature" selection before I draw the new rectangle? When I hover over the existing panel's corner to start the new rectangle, I don't see a dot appear over the panel's corner to verify that it's precise on the corner.

[jhackney1972]

Just a guess. since you did not submit a model, it sounds like you are not using the "Project" command to obtain a vertex from existing geometry.  Please submit your model and the Forum users can help you out.  If you do not know how to attach your Fusion 360 model follow these easy steps. Open the model in Fusion 360, select the File menu, then Export and save as a F3D or F3Z file to your hard drive. Then use the Attachments section, of a forum post, to attach it.

[jeff_strater · Accepted solution]

My guess is that you do not have this preference enabled:

with this option on, you would not have to manually project geometry into the sketch - the geometry from the face you sketched on will automatically be projected into the sketch, and you should be able to snap the corner of the rectangle precisely to this line in the sketch.

[atdNMH7S]

Thanks to both posters for the suggested solutions. I suspect that either would work, but I happened to implement jeff.strater's first and it fixed my problem.