1. Isosceles and Equilateral Triangles
Chapter 4.6
Isosceles and Equilateral Triangles

2. Concept

3. A. Name two unmarked congruent angles.
Congruent Segments and Angles
A. Name two unmarked congruent angles.
BCA is opposite BA and A is opposite BC, so BCA  A.
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Answer: BCA and A

4. B. Name two unmarked congruent segments.
Congruent Segments and Angles
B. Name two unmarked congruent segments.
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BC is opposite D and BD is opposite BCD, so BC  BD.
Answer: BC  BD

5. A. Which statement correctly names two congruent angles?
A. PJM  PMJ
B. JMK  JKM
C. KJP  JKP
D. PML  PLK

6. B. Which statement correctly names two congruent segments?
A. JP  PL
B. PM  PJ
C. JK  MK
D. PM  PK

7. Concept

8. Subtract 60 from each side. Answer: mR = 60 Divide each side by 2.
Find Missing Measures
A. Find mR.
Triangle Sum Theorem
mQ = 60, mP = mR
Simplify.
Subtract 60 from each side.
Answer: mR = 60
Divide each side by 2.

9. Find Missing Measures
B. Find PR.
Answer: PR = 5 cm

10. Example 2a
A. Find mT.
A. 30°
B. 45°
C. 60°
D. 65°

11. B. Find TS.
A. 1.5
B. 3.5
C. 4
D. 7

12. ALGEBRA Find the value of each variable.
Find Missing Values
ALGEBRA Find the value of each variable.

13. Find the value of each variable.
A. x = 20, y = 8
B. x = 20, y = 7
C. x = 30, y = 8
D. x = 30, y = 7

14. Prove: ΔENX is equilateral.
Apply Triangle Congruence
Given: HEXAGO is a regular polygon. ΔONG is equilateral, N is the midpoint of GE, and EX || OG.
Prove: ΔENX is equilateral.
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