5.5 Inequalities in Triangles DOM Can you figure out the puzzle below??? Domino
Comparison Property of Inequality b c Comparison Property of Inequality: If a = b + c, and c > 0, then a > b.
Proof of Comparison Property of Inequality Given: a = b + c, c > 0 Prove: a > b Statements Reasons 1. 2. 3. 4. 5. c > 0 b + c > b + 0 b + c > b a = b + c a > b
Theorem Corollary to the Triangle Exterior Angle Theorem: The measure of an exterior angle of a triangle is greater than the measure of each of its remote interior angles. Insert figure from home
Application Given the figure below, explain why . 1. 1. 2. 2. 3. 3. Statements Reasons 1. 2. 3. 1. 2. 3. 5
Theorem Theorem 5-10: If two sides of a triangle are not congruent, then the larger angle lies opposite the longer side. Insert figure from home 6
Example List the angles of the following figure in order from smallest to largest. 7
Theorem Theorem 5-11: If two angles of a triangle are not congruent, then the longer side lies opposite the larger angle. Insert figure from home 8
Sides of a Triangle List the sides of the following triangle in order from shortest to longest. Determine which segment is shortest in the following diagram.
Theorem Theorem 5-12: Triangle Inequality Theorem: The sum of the lengths of any two sides of a triangle is greater than the length of the third side. Insert figure from home 10
Theorem Can a triangle have sides with the given lengths? a) 7 ft, 3 ft, 8 ft b) 10 cm, 6 cm, 3 cm A triangle has sides of lengths 8 cm and 10 cm. Describe the lengths possible for the third side. 11
5.5 Inequalities in Triangles HW 5.5: #1-25 (1st column), 32, 33, 35 p.192: #3-4, 11, 22, 24-26 Scrambled Eggs
Midterm Review Given the figure below, name the type of angle pairs given.
Midterm Review Find . Justify each answer. 1) 2) 135° 1 2 14
Midterm Review Find x in the following polygon. x° 125° 125° 15
Midterm Review Find the equation of a line that goes through the point (-2, 1) and (3,2). Find the equation of a line parallel to y + 3x = 5 that goes through the point (-3, 5). 16