looks like the Dresden plate with more petals. this one has 36, so that would be 10 deg. I have an assortment of wedge rulers, they are fun to play with. I put a bit of tape on each one with the number of petals needed to complete a circle.
Another idea if you want to use up jelly rolls is the Checkered Dresden. I used that idea and made a bunch of plates in different sizes, and then arranged them to look like a bunch of gears that driving each other. I have them all pinned on but have not decided exactly how I want to sew them on.