If you tilt the foot(the metal part that is tiltable) to 35 degrees----that will happen before you get to 45 degrees---it starts at perpendicular(if you use 90 it is confusing) and the tilt degrees start at 0, then one degree, then two---up to 45 Degrees.

Making a matching but opposite aggle cut with a jigsaw means the other cut has to be made in the reverse direction is the pieces are not identical. If the pieces are identical but mirror, makes no difference which direction they are cut.

The total angle when the two pieces are mated will be 70 degrees.

Handymac, thank you. That helps a lot - think of perpendicular as zero degrees instead of 90. I ended up at the same place, I think - 35 degrees off of the perpendicular is a 55-degree angle from the other direction. And THAT matches the picture in my book, so I feel better! The plans gave directions for making a jig to set the blade angle, and the picture was showing a 55-degree angle instead of 35. But if I think of it from the perpendicular as zero, that makes sense...Thanks again! I think I'm ready to make my cuts today!