I made a circle using the Ellipse tool and used the Line Segment tool to make lines to divide it into 12 sections. I used the Shape Builder tool to make it into 12 separate shapes. When I go to use the Direct Selection tool, the option to round corners is on almost all the corners except 3 of the corners in the middle. What could be the reason for this? Thanks!
I would suggest pulling one of the segments that doesn't have the round corner option out of the circle and make sure that the path is closed at the point where there is no round corner icon showing.
I looked closer and some of the triangles had two anchor points at what looked like just one. I think this was due to some of the line segments not crossing exactly in the middle. Thanks for the help!
It seems like the Shape Builder tool is not very accurate and sometimes creates multiple anchor points very close to each other.
You could try to use Pathfinder Divide, but first set the Pathfinder precision in the Pathfinder Options to a very small number like 0,001 pt.
It turns out that some of the triangles had two anchor points where it looked like there was just one. It was due to some line segments not crossing at exactly the middle of the circle. Thanks for the tip!