BELLWORK Given: 1 ≌ 2, BC ≌ DA Prove: EC ≌ EA B D C A E F 1 2 Given: A ≌ D, AB ≌ CD, AF ≌ ED Prove: ∆FAC ≌ ∆EDB A B C D E F

Objective Vocabulary Base angles Vertex angle Base legs Unit 4 – Triangle Congruence 4.9 Isosceles and Equilateral Triangles Objective Use properties of isosceles and equilateral trianlges. Vocabulary Base angles Vertex angle Base legs

Isosceles Triangle: At least 2 sides  Unit 4 – Triangle Congruence 4.9 Isosceles and Equilateral Triangles Isosceles Triangle: At least 2 sides  Angles opposite of legs are  vertex angle If I know then I know legs base base angles If two angles are , then their opposite sides are also  If I know then I know

a y 6x 50° b 12 The perimeter = 30 10 x 40° s r The perimeter = 21 Unit 4 – Triangle Congruence 4.9 Isosceles and Equilateral Triangles 6x The perimeter = 30 12 y 50° a b x The perimeter = 21 10 40° r s

Equilateral Triangle: three sides  Unit 4 – Triangle Congruence 4.9 Isosceles and Equilateral Triangles Equilateral Triangle: three sides  If equilateral then equiangular If I know then I know If equiangular then equilateral If I know then I know

What are the values of each variable? Unit 4 – Triangle Congruence 4.9 Isosceles and Equilateral Triangles What are the values of each variable? 6x 2x 3x-y 5x + 4 z What is the perimeter?

CLASSWORK – match each problem with an answer Unit 4 – Triangle Congruence 4.9 Isosceles and Equilateral Triangles CLASSWORK – match each problem with an answer 2. 2b 3b+5 50° c 3. 40° a 1. Answers 40 114 36 55 25 45 5. 2y 4.

Unit 4 – Triangle Congruence 4.7 CPCTC Given: Isosceles ∆PQR, base QR, PA  PB Prove: AR  BQ

Unit 4 – Triangle Congruence 4.9 Isosceles and Equilateral Triangles Homework: 4.9(288): 15,16,19,28,29,33,34 14)33 16) 31 18)48 28)58,64,122 34)3