Weird Triangles printing

I have printed a manual through adobe reader (10.1.16) I have no idea what was used to create the file, printing to a regular printer (brother)  Its not really a big deal they don't show on all the pages they seem to be random, I have tried reprinting and it still prints the lines, the lines do not show in the document just the print out. They are perfect triangles, they seem to vary a bit in size and I checked in a 54 page document I have 9 with the triangles on them. scanned one of the pages to show what I mean:

Any idea how to remove these from the print out?

Thanks

Bill