This is how I laid out the dovetails and the mitered shouldered dovetail for the bottom edge.
First I marked out the area that needs to be dovetailed and measured that with my dividers.
I wanted four tails, so I laid out the sector to fit the dividers at 8 ..
.. and then set the second set of dividers to 2 to be able to produce 4 tails.
Then I walked out the 4 tails adding a tiny bit to allow for pin spacing.
Ta da! 4 tails and pins.
This is how I cut the mitered dovetail to cover the slot that will hold the bottom of the cabinet.
And behold the mitered dovetail.
PS. Wanna know where to get a sector? Go here ->
CABINETMAKER’S SECTOR
Wanna know how to use a sector?? Or make a cheap one? Go here -> http://www.burn-heart.com/sector
sheworkswood.com 
Sweet!!
Great to see you back on the blog, Marilyn!
Yes, Instagram is a big distraction. 🙂
Thanks for the sector lesson! I understand it in principle but it’s helpful to see it in action on a real project/need. Do you know if anyone has a tutorial on how to use a sector for this or for that?
Thanks Shawn! There are several tutorials. The best place to look is at http://www.burn-heart.com/sector. He has a tutorial and then links to several other spots.