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2.3/2.4 Polygons!. Learning Objective: to identify properties of polygons, and to find the sums of the measures of the interior and exterior angles of polygons. Warm-up (IN). Do you know the term for… A 3-sided figure? A 4-sided figure? A 5-sided figure? A 6-sided figure? A 7-sided figure?
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2.3/2.4 Polygons! Learning Objective: to identify properties of polygons, and to find the sums of the measures of the interior and exterior angles of polygons Warm-up (IN) • Do you know the term for… • A 3-sided figure? • A 4-sided figure? • A 5-sided figure? • A 6-sided figure? • A 7-sided figure? • …????
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! triangle quadrilateral pentagon hexagon heptagon octagon nonagon decagon n-gon
Learning Objective: to identify properties of polygons, and to find the sums of the measures of the interior and exterior angles of polygons Concave Polygon - “caves” in Convex Polygon - doesn’t “cave” in Concave decagon All sides equal Equilateral Polygon - All angles equal Equiangular Polygon - Convex hexagon All sides and angles equal Regular Polygon - regular hexagon
Learning Objective: to identify properties of polygons, and to find the sums of the measures of the interior and exterior angles of polygons O U H S E To name a polygon - Name vertices in consecutive order! Pent. HOUSE Or??? or Pent. OUSEH CKC p. 75
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 1 180 180 4 2 360 180 quad. 5 540 3 180 pentagon 180 720 4 6 hexagon 180 n-2 n-2(180) n n-gon
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
Learning Objective: to identify properties of polygons, and to find the sums of the measures of the interior and exterior angles of polygons Ex 2 – what polygon, if any, has angle measures that add up to 2000º? EH…not a whole number, so no polygon…
Learning Objective: to identify properties of polygons, and to find the sums of the measures of the interior and exterior angles of polygons 4 3 5 1 2 Sum of exterior angles of a polygon – 3 2 1 Sum of exterior angles of a polygon – Yep…always!
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!! HW – p. 76 #1-4, 17-23 odd p. 83 #1-9, 19-31 odd