2 PolygonsDefinition:A closed figure formed by a finite number of coplanar segments so that each segment intersects exactly two others, but only at their endpoints.These figures are not polygonsThese figures are polygons
3 Classifications of a Polygon Convex:No line containing a side of the polygon contains a point in its interiorConcave:A polygon for which there is a line containing a side of the polygon and a point in the interior of the polygon.
4 Classifications of a Polygon Regular:A convex polygon in which all interior angles have the same measure and all sides are the same lengthIrregular:Two sides (or two interior angles) are not congruent.
6 Convex Polygon Formulas….. Diagonals of a Polygon:A segment connecting nonconsecutive vertices of a polygonFor a convex polygon with n sides:The sum of the interior angles isThe measure of one interior angle isThe sum of the exterior angles isThe measure of one exterior angle is
7 Examples….. Sum of the measures of the interior angles of a 11-gon is The measure of an exterior angle of a regular octagon isThe number of sides of regular polygon with exterior angle 72 ° isThe measure of an interior angle of a regular polygon with 30 sides