1. Polygons Lesson 13-4

2. What is a polygon? A polygon is a simple, closed, two-dimensional figure formed by three or more line segments (sides). Closed? Two-dimensional? Three or more sides?

3. What makes a polygon regular? A regular polygon is a polygon having all sides congruent and all angles congruent. What does congruent mean? Congruent sides Congruent angles

4. Triangles Polygon with 3 sides Triangles can be classified by their sides and angles.

5. Types of Triangles Scalene Triangle – no sides congruent Isosceles Triangle – two sides congruent Equilateral Triangle – all sides and angles congruent Acute Triangle – all acute angles Right Triangle – one right angle ObtuseTriangle – one obtuse angle

6. Quadrilaterals Trapezoid – 1 pair of opposites sides parallel Parallelogram – opposites sides congruent and parallel with opposite angles congruent Rhombus – parallelogram with congruent sides Rectangle – parallelogram with all right angles Square – rectangle with all sides equal polygon with 4 sides

7. Polygon with 5 sides Which pentagon is regular? Pentagon

8. Hexagon Polygon with 6 sides Which hexagon is regular?

9. Heptagon Polygon with 7 sides Which heptagon is regular?

10. Octagon Polygon with 8 sides Which octagon is regular?

11. Name each polygon 1. Right Isosceles Triangle 2. Trapezoid 3. Regular Pentagon 4. Parallelogram 5. Obtuse Scalene Triangle 6. Octagon