placement

If I draw a rectangle on the front plane, and extrude it by 100mm.. Then rotate my view and start sketching on the right plane.. It's like the sketch tools don't acknowledged that there's now an object, edge, or line there. I need it to 'snap to' so I can place some lines and holes in the right spots, relative to the…

Below are some neodymium magnets, placed on a plastic part. They've been placed freehand (XYZ Transform, No Mates), but I'd like them to be precise. Is there a way to do that? Would be nice if I could use the existing lines, and place them an equal distance from the surrounding edges and/or fillets, etc. FYI: In reality,…