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Objective: The students will be able to identify congruent triangles, find corresponding parts of congruent triangles and transform congruent triangles.
Chapter 4 – Lesson 2 Congruent Triangles
Vocabulary Corresponding Matching according to some agreed rule
Definition Congruent Triangles We say triangles ABC and DEF are congruent if and only if all their corresponding parts are congruent (CPCTC) We write ABC DEF A corresponds to D; B to E; C to F
ARCHITECTURE A tower roof is composed of congruent triangles all converging toward a point at the top. Name the corresponding congruent angles and sides of HIJ and LIK. HIJ LIK Answer: Since corresponding parts of congruent triangles are congruent, Example 3-1a
Name the congruent triangles. ARCHITECTURE A tower roof is composed of congruent triangles all converging toward a point at the top. Name the congruent triangles. Answer: HIJ LIK Example 3-1b
The support beams on the fence form congruent triangles. b. Name the congruent triangles. a. Name the corresponding congruent angles and sides of ABC and DEF. Answer: Answer: ABC DEF Example 3-1c
Vocabulary Congruence Transformation A function that changes a triangle into a new triangle congruent to the original We’ll look at 3 congruence transformations: Slide Turn Flip
Congruence Transformation Slide Slides are often called translations
Congruence Transformation Turn Turns are often called rotations
Congruence Transformation Flip Flips are often called reflections
Answer: RST is a turn of RST. COORDINATE GEOMETRY The vertices of RST are R(─3, 0), S(0, 5), and T(1, 1). The vertices of RST are R(3, 0), S(0, ─5), and T(─1, ─1). Name the congruence transformation for RST and RST. Answer: RST is a turn of RST. Example 3-2d
b. Name the congruence transformation for ABC and ABC. Answer: turn Example 3-2g
Theorem 4.3 Third Angle Theorem If two angles of a triangle are congruent to two angles of a second triangle then the third angles of the two triangles are also congruent
Kahoot!
Lesson Summary: Objective: The students will be able to identify congruent triangles, find corresponding parts of congruent triangles and transform congruent triangles.
Preview of the Next Lesson: Objective: The students will be able to Prove Congruence – SSS and SAS.
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