Warmup Triangle Sum Theorem – if you add up the measures of all interior angles of any triangle, you will get 180⁰ For each triangle, find the measure.

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Presentation transcript:

Warmup Triangle Sum Theorem – if you add up the measures of all interior angles of any triangle, you will get 180⁰ For each triangle, find the measure of angle 1:

Warmup

Warmup

Classifying Triangles by Sides and by Angles Part 2 Chp 5.1

Triangle Sum Theorems Triangle Sum Theorem – if you add up the measures of all interior angles of any triangle, you will get 180⁰ Corollary to the Triangle Sum Theorem – the acute angles of a right triangle are complementary (add up to 90⁰)

Triangle Angle Measures & Theorems Exterior Angle Theorem – the measure of an exterior angle = sum of measures of the two non-adjacent interior angles

Properties of Triangle Congruence Reflexive - ΔABC ΔABC Symmetric - If ΔABC ΔDEF, then ΔDEF ΔABC Transitive - If ΔABC ΔDEF and ΔDEF ΔJKL, then ΔABC ΔJKL

Examples: Corollary to the Triangle Sum Theorem

Example: Exterior Angle Theorem

Example: Using Everything You Know Find all the numbered angles: