Download the .ggb file and export to PNG or SVG at the resolution you want (File -> Export -> Graphics View as Picture).
The protractor is transparent (apart from where the numbers are) so is ideal for adding to a GeoGebra worksheet.
Example: http://www.geogebratube.org/material/show/id/22760
SVG Example: http://tube.geogebra.org/material/show/id/324047