Slotted Protractor

Slice with a colour change at 1.00mm so the numbers are easier to read.  

Marked in 1 degree incrments.

The slots make it easier to see the angle when measuring a physical object that is shorter than the radius of the protractor.  Also, you can use the slots to draw lines at the major angles.

Scale X & Y to make any size.  The small blue protractor in to photo is the size of the STL (80mm diameter).  The larger green one is scaled up to 200%.