Ch4.1 Triangles Theorems
- 1. Ch4.1_TrianglesTheorems.notebook October 24, 2011 Chapter 4.1 Triangles and Theorems 1
- 2. Ch4.1_TrianglesTheorems.notebook October 24, 2011 Review All angles in a triangle add up to 1800 Acute triangles: all angles are less than 900 Obtuse triangles: 1 obtuse angle, 2 acute angles Right triangles: 1 right angle, 2 acute angles 2
- 3. Ch4.1_TrianglesTheorems.notebook October 24, 2011 Review Equilateral triangles: all sides are same length Isosceles triangles: Two sides are same length Scalene triangles: all sides have different lengths 3
- 4. Ch4.1_TrianglesTheorems.notebook October 24, 2011 600 200 600 300 4
- 5. Ch4.1_TrianglesTheorems.notebook October 24, 2011 Exterior Angle Theorem An exterior angle of a triangle is equal to the sum of the 2 nonadjacent angles in the triangle. 600 0 1200 60 600 Find x x 300 5
- 6. Ch4.1_TrianglesTheorems.notebook October 24, 2011 Proof of External Angle Theorem C0 X0 Ao Bo 0 X + A = 180 Supplementary angles 0 A + B + C = 180 Triangle sum theorem X + A = A + B + C Transitive Property X = B + C Addition property of equality 6