6.1 Polygons 6.2 Properties of Parallelograms Essential Question: How would you describe a polygon?

Polygons  Plane figure formed by three or more sides.  Each endpoint of a side is a vertex.  To name a polygon, list its vertices in order.

Polygons are named by the number of sides they have: Number of Sides Type of Polygon 3Triangle 4Quadrilateral 5Pentagon 6Hexagon 7Heptagon Number of Sides Type of Polygon 8Octagon 9Nonagon 10Decagon 12Dodecagon nn-gon

Describing Polygons  Convex  Concave; (Hint: side is caved in)

 Equilateral  Equiangular  Regular – all angles and sides are the same. *do #1-13 from overhead

 Diagonal – segment that joins two vertices.

Interior Angles of a Quadrilateral  Angles of a quadrilateral add up to 360 °. *problems from overhead

Assignment  P.325 #4-20, 24-26, 37-39, 41-45

6.2 Parallelograms  Parallelogram- quadrilateral with both pairs of opposite sides parallel

4 Properties of Parallelograms  If a quadrilateral is a parallelogram, then its opposite sides are congruent.

 If a quadrilateral is a parallelogram, then its opposite angles are congruent.

 If a quadrilateral is a parallelogram, then its consecutive angles are supplementary.

 If a quadrilateral is a parallelogram, then its diagonals bisect each other.

Examples: Using Properties of Parallelograms:

Assignment  Complete #1-21 from overhead  P. 333 #2-37 depending on time