Use the protractor to find the measure of the angle:
https://cdn.lti.glynlyon.com/interactives/chm/cdn_harness/cdn_harness.html?base=global&file=dla_protractor/js/protractor.js&dataBasePath=014e4175-daf1-4e3c-be4d-f952523a8c48&dlaFile=prt_mat07u08c01l01d.dla

Click once to pick up the protractor. Use your mouse to move it until it lines up correctly over the angle. Click again to lock the protractor into place.


165°

15°

10°

170°