1. 4-6 Isosceles and Equilateral Triangles
Ms. Andrejko

2. Real World

3. Vocabulary Legs- the two congruent sides of an isosceles triangle
Vertex Angles- the angle with sides that are the legs
Base Angles- the two angles formed by the base and the congruent sides

4. Theorems/Corollaries
T If 2 sides of a triangle are congruent, then the angles opposite those sides are congruent
T if 2 angles of a triangle are congruent then the sides opposite those angles are congruent
C A triangle is equilateral if and only if it is equiangular
C 4.4- Each angle of an equilateral triangle measures 60°.

5. Examples

6. Practice

7. Examples Refer to the figure 1. If AC ≅ AD, name two congruent angles.
2. If BE ≅ BC, name two congruent angles.

8. Practice Refer to the figure
3. If ∠EBA ≅ ∠EAB, name two congruent segments.
4. If ∠CED ≅ ∠CDE, name two congruent segments.

9. Example/Practice 1. m∠KML 2. m∠HMG 3. m∠GHM
4. If m∠HJM = 145, find m∠MHJ.
5. If m∠G = 67, find m∠GHM.

10. Example

11. Practice

12. Mixed Review
110 70 30

13. Mixed Review 50
12.
AAS or ASA

14. Mixed Review 20 90 40