 # Polygons Closed figure made up of line segments

## Presentation on theme: "Polygons Closed figure made up of line segments"— Presentation transcript:

Polygons Closed figure made up of line segments
Concave Polygon-can have reflex angles :One or more angles greater than 180o Convex Polygon-all angles greater than 0o and less than 180o

congruent Same size and same shape

similar Same shape, not necessarily the same size

Regular Polygons Polygon with all sides congruent and all angles congruent Special Regular Polygons Equilateral triangle Square

Triangle Polygon with three sides A B C Symbol: ABC

parallelogram kite rectangle rhombus square

Parallelogram Quadrilateral with opposite sides parallel and congruent

Rectangle Parallelogram with four right angles

Rhombus Parallelogram with four congruent sides

Square Parallelogram with four right angles and four congruent sides

Trapezoid Quadrilateral with one pair of parallel sides

Pentagon Polygon with five sides Regular Pentagon

Hexagon Polygon with six sides Regular Hexagon

Heptagon Polygon with seven sides Regular Heptagon

Octagon Polygon with eight sides Regular Octagon

Decagon Polygon with ten sides convex concave

Dodecagon Polygon with twelve sides convex concave

Total Degrees in Polygons
Figure Sides 3 # of triangles 1 x 180 = Total degrees 1800 4 2 x 180 = 3600 5 3 x 180 = 5400 180 180 180 180 180 180

Complete the Table Do you see a pattern?
Figure Sides # of triangles Total degrees 6 7 8 12 n

Regular Polygons All sides congruent All angles congruent

Angle Measure Regular Polygons
What is degree measure of each angle of a regular polygon? E 5400 Total degrees = ?? A D Degrees = ??? C B A 1080 E D B C

Angle Measure Regular Polygons
Equilateral triangle = Measure each angle = 600 Square = Measure each angle = 900

Angle Measure Regular Polygons
Regular Hexagon = ?? Measure each angle = ?? Regular Octagon = ?? Measure each angle = ??

Polygons The End