1. Quadrilaterals Sec 6.1 GOALS: To identify, name, & describe quadrilaterals To find missing measures in quadrilaterals

2. Polygons Polygon – a figure that has three or more sides vertex side a plane figure a closed figure three or more noncolllinear sides each side intersects exactly two other sides at the vertices Specifically:

3. Polygon or not? Identify whether the following figures are polygons.

4. Naming Polygons Polygons are named by the number of sides they have. Number of sidesName 3triangle 4quadrilateral 5pentagon 6hexagon 7heptagon 8octagon 9nonagon 10decagon n n-gon

5. Convex and Concave Polygons Convex Polygon – a polygon where no line that contains a side of the polygon contains a point in the interior of the polygon. Point in the interior! Convex Polygon Concave Polygon

6. Example Name of Polygon Convex or Concave? #1 #2

7. Regular Polygon Regular Polygon – a polygon that is both equilateral and equiangular. Are the following polygons regular?

8. Diagonal of a Polygon A segment that joins two nonconsecutive vertices. Polygon ABCDE Diagonals BE and BD

9. Angle Measures in Quadrilaterals The sum of the measures of the interior angles of a quadrilateral is 360 degrees. Theorem 6.1

10. Example Find the value of y in quadrilateral WXYZ.

11. Example Find the value of x in quadrilateral WXYZ. Then find the measure of angle X and Y.

12. Example Solve for x and y. Then find the angle measures.

13. Homework Page 325- See assignment guide