6.1 Polygons Convex verse Concave

Definition of a Polygon A polygon is a figure on a plane with three or more sides that meet at a vertex.

Name of this Polygon ABCD, CDAB, or DABC You want to list the vertices in some order.

Polygons are named by their sides 3 sides – Triangle 4 sides – Quadrilateral 5 sides – Pentagon 6 sides – Hexagon 7 sides – Heptagon 8 sides – Octagon 9 sides – Nonagon 10 sides – Decagon 11 sides - Hendecagon 12 sides – Dodecagon 13 sides - Tridecagon or Triskaidecagon 14 sides - Tetradecagon or Tetrakaidecagon 14 N sides – n-gon

Polygons are named by their sides 3 sides – Triangle 4 sides – Quadrilateral 5 sides – Pentagon 6 sides – Hexagon 7 sides – Heptagon 8 sides – Octagon 9 sides – Nonagon 10 sides – Decagon 11 sides - Hendecagon 12 sides – Dodecagon 13 sides - Tridecagon or Triskaidecagon 14 sides - Tetradecagon or Tetrakaidecagon 14 N sides – n-gon

Polygons are named by their sides 3 sides – Triangle 4 sides – Quadrilateral 5 sides – Pentagon 6 sides – Hexagon 7 sides – Heptagon 8 sides – Octagon 9 sides – Nonagon 10 sides – Decagon 11 sides - Hendecagon 12 sides – Dodecagon 13 sides - Tridecagon or Triskaidecagon 14 sides - Tetradecagon or Tetrakaidecagon 14 N sides – n-gon

Polygons are named by their sides 3 sides – Triangle 4 sides – Quadrilateral 5 sides – Pentagon 6 sides – Hexagon 7 sides – Heptagon 8 sides – Octagon 9 sides – Nonagon 10 sides – Decagon 11 sides - Hendecagon 12 sides – Dodecagon 13 sides - Tridecagon or Triskaidecagon 14 sides - Tetradecagon or Tetrakaidecagon 14 N sides – n-gon

Polygons are named by their sides 3 sides – Triangle 4 sides – Quadrilateral 5 sides – Pentagon 6 sides – Hexagon 7 sides – Heptagon 8 sides – Octagon 9 sides – Nonagon 10 sides – Decagon 11 sides - Hendecagon 12 sides – Dodecagon 13 sides - Tridecagon or Triskaidecagon 14 sides - Tetradecagon or Tetrakaidecagon 14 N sides – n-gon

Polygons are named by their sides 3 sides – Triangle 4 sides – Quadrilateral 5 sides – Pentagon 6 sides – Hexagon 7 sides – Heptagon 8 sides – Octagon 9 sides – Nonagon 10 sides – Decagon 11 sides - Hendecagon 12 sides – Dodecagon 13 sides - Tridecagon or Triskaidecagon 14 sides - Tetradecagon or Tetrakaidecagon N sides – n-gon

Polygons are named by their sides 3 sides – Triangle 4 sides – Quadrilateral 5 sides – Pentagon 6 sides – Hexagon 7 sides – Heptagon 8 sides – Octagon 9 sides – Nonagon 10 sides – Decagon 11 sides - Hendecagon 12 sides – Dodecagon 13 sides - Tridecagon or Triskaidecagon 14 sides - Tetradecagon or Tetrakaidecagon 14 N sides – n-gon

Polygons are named by their sides 3 sides – Triangle 4 sides – Quadrilateral 5 sides – Pentagon 6 sides – Hexagon 7 sides – Heptagon 8 sides – Octagon 9 sides – Nonagon 10 sides – Decagon 11 sides - Hendecagon 12 sides – Dodecagon 13 sides - Tridecagon or Triskaidecagon N sides – n-gon

Definition of Convex and Concave polygons A polygon is convex if any line can pass through two points in the polygon and without going outside of the polygon.

Remember definitions Equilaterial – All sides equal Equilangluar – All angles equal Regular Polygon – All sides and angles equal.

Regular Polygon – All sides and angles equal

Theorem The interior angles of a Quadrilateral add to 360º The interior angles of any polygon is (n – 2) x 180º Where n is the number of sides

Homework Page 326 – 328 #18, 19, 21 – 23, 27 – 29, 37 – 39,