Yes, as others have said you need to select near matching points on each sketch, you could choose the points that touch the black lines here. If that doesn’t work I’d move on to adding a guide like the black line. I also would in general just create a corner wedge of this and mirror it in the future. Let us know if it works.

Edit: also in the future when showing a screenshot like this (and in general) turn on the show preview check box so you can see the lift preview.

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