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Polygons. Polygons. Definition:. 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 polygons. These figures are polygons. Naming Polygons. Use capital letters
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Polygons Definition: 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 arenot polygons These figures are polygons
Naming Polygons • Use capital letters • List them in consecutive order B A C Plane ABCDE Plane DEABC Plane CBAED Etc… E D
Polygon Names Triangle 3 sides 4 sides Quadrilateral 5 sides Pentagon 6 sides Hexagon 7 sides Heptagon 8 sides Octagon 9 sides Nonagon 10 sides Decagon Dodecagon 12 sides n sides n-gon
Classifications of a Polygon Convex: No line containing a side of the polygon contains a point in its interior Concave: A polygon for which there is a line containing a side of the polygon and a point in the interior of the polygon.
Examples: Tell whether each is a polygon. If a polygon, is it concave or convex?
Classifications of a Polygon Regular: A convex polygon in which all interior angles have the same measure and all sides are the same length Equilateral: All sides are congruent Equiangular: All interior angles are congruent Irregular: Two sides (or two interior angles) are not congruent.
Examples: A rack for billiard balls is shaped like a regular triangle. Find the length of each side.
Examples: Find the value of x so that the polygon is equilateral or equiangular.
Find the value of x so that the polygon is equilateral or equiangular.