1. Chapter 6 Polygons

2. Definitions Polygon – many sided figure 3 sided – triangles 4 sided – quadrilaterals 5 sided – pentagons 6 sided – hexagons 7 sided – heptagons 8 sided – octagons 10sided – decagons More sides – n gons

3. Name These Polygons Triangle Octagon Hexagon Quadrilateral Pentagon

4. Polygon Formulas Interior angles The sum = 180(n-2) *n is number of sides Exterior angles The sum = 360 degrees ***Any adjacent Interior and Exterior Angles are supplementary Because they form a straight line

5. Regular Polygons Regular Polygons – all sides/angles are congruent to each other Each interior angle = 180(n-2)/n Each interior angle = 360/n

6. Example This is a regular Pentagon Find the measure of each exterior Angle 360/n = 360/5 = 72 Find the measure of each Interior Angle 180(n-2)/n = 180(5-2)/5 = 108 deg 10872

7. Example 2 This is a non regular Pentagon 80 100 110 140 x y Find the value of x and y First find the sum of interior Angles = 180(n-2) = 180(5-2) = 540 Then find x : All other angles total 430 540 – 430 = 110 Lastly find y 180 – 110 = 70 110 70

8. Quadrilaterals Quadrilaterals have 4 sides

9. Types of Quadrilaterals Rectangles Parallelograms Rhombuses Squares Opposite Sides Parallel Opp. Sides All rt Opp. Sides Same as Rect. But ALL sides Same as parallelograms, But all sides

10. Parallelograms Rhombuses What’s in common? Opp. Sides parallel So they’re both Parallelograms

11. Squares Rhombuses What’s in common? Opp Sides are parallel All sides are congruent They’re both Parallelograms

12. Give all the possible names of this Parallelogram If 4 sides are congruent Rhombuses Squares