Unfortunately, the .jpeg that you attached had no content. So, I have done up an example of a protrator where the student simply has to use the print graphic to tell the angles. They are not actually measuring them.
Protractors can provide an accurate angle measurement to within 5 degrees. The rays of an angle to be measured with a braille protractor must be at least 3 inches (7.5 centimeters) in length. There should be a 1-inch margin all around the tactile to allow for placement of the actual braille protractor.
If though, as I said, you are showing an illustration of a protractor, it still must be simplified considerably in order to fit the essential information and still have sufficient room (1/8 inch minimum) between lines and labels. Please see attached Word document for print and tactile examples. Allow me to ammend my earlier statement and say that you may also need to show 5 degree tick marks (shorter than the 10 degree tick marks). I have included an example of one that is TOO detailed and a better one that has been simplified. I hope this is helpful.