Types of Angles What they do... Round a point Add up to 360o On a straight line Add up to 180o Vertically Opposite Equal In a triangle Add up to 180o In a quadrilateral (4-sided polygon) Add up to 360o Alternate (Z-angles) Equal Corresponding (F-angles) Equal Supplementary (C or U angles) Add up to 180o Bearings Notes Always use three figures. Always draw North lines. Always measure from North being 0o. Always measure clockwise. Always put in pencil lines connecting the points and don't rub them out at the end. Always put your protractor on the place you're measuring from and not to. Be as accurate as your can (sharp pencil, lean over diagram!).