1. 2.3/2.4 Polygons! Warm-up (IN) Learning Objective: to identify properties of polygons, and to find the sums of the measures of the interior and exterior angles of polygons Do you know the term for… 1.A 3-sided figure? 2.A 4-sided figure? 3.A 5-sided figure? 4.A 6-sided figure? 5.A 7-sided figure? 6.…????

2. Notes A closed plane figure whose sides are segments that intersect only at their endpoints. Polygon - Put the terms that you don’t know (by heart!!) in your notes. Key terms on the left! # of sidesname 3 4 5 6 7 8 9 10 n triangle quadrilateral pentagon hexagon heptagon octagon nonagon decagon n-gon

3. Learning Objective: to identify properties of polygons, and to find the sums of the measures of the interior and exterior angles of polygons Convex Polygon - Concave Polygon - “caves” in doesn’t “cave” in Equilateral Polygon - All sides equal Equiangular Polygon - All angles equal Regular Polygon - All sides and angles equal Concave decagon Convex hexagon regular hexagon

4. Learning Objective: to identify properties of polygons, and to find the sums of the measures of the interior and exterior angles of polygons To name a polygon - Name vertices in consecutive order! H O U S E Pent. HOUSE or Pent. OUSEH Or??? CKC p. 75

5. Name# of sides # of ‘s formed Sum of measures of Sum of measures of polygon EXPLORE! 1 – draw each of the shapes on graph paper, then draw all of the diagonals from one vertex, and complete the table. triangle 3 1 180 quad. pentagon hexagon n-gon 4 2 180 360 5 3 180 540 6 4 180 720 n n-2 180 n-2(180)

6. Learning Objective: to identify properties of polygons, and to find the sums of the measures of the interior and exterior angles of polygons Sum of interior angles of a polygon - n = #of sides Ex 1 – A barn is shaped like the polygon in the diagram. Find the measure of each unknown angle in the diagram

7. Ex 2 – what polygon, if any, has angle measures that add up to 2000º? Learning Objective: to identify properties of polygons, and to find the sums of the measures of the interior and exterior angles of polygons EH…not a whole number, so no polygon…

8. Sum of exterior angles of a polygon – Learning Objective: to identify properties of polygons, and to find the sums of the measures of the interior and exterior angles of polygons 1 4 2 3 5 1 2 3 Sum of exterior angles of a polygon – Yep…always!

9. Ckc – P. 82

10. HW – p. 76 #1-4, 17-23 odd p. 83 #1-9, 19-31 odd Out –explain how to find the sum of the interior angles of a polygon. (ticket out!) Summary – I think I understand… Or…I’m not sure about…. POW!!