1. Section 4.7: Isosceles and Equilateral Triangles Understand the relationship between Sides and Angles in Isosceles and Equilateral Triangles and be able to use that relationship to solve problems.

2. Vocabulary of Isosceles Triangles Vertex Angle Leg Base Angles

3. Theorem 4.7: Base Angles Theorem. Leg Base Angles A CB

4. Theorem 4.7: Base Angles Theorem Proof J K L

5. Theorem 4.8: Converse Base Angles Theorem. Leg Base Angles A CB

6. This is the Transamerica Building. You need to reproduce the pyramid on the top of the building to create a logo for the Transamerica Corp. The information you have been given is that the angle at the lower right hand corner of the pyramid is approximately 85°. In order to create a logo that visually matches the building you will need to find the measure of the other two angles. Describe your method:

7. Equilateral Triangles Base Angles Corollary If two congruent sides means two congruent angles, then three congruent sides must mean three congruent angles

8. Corollaries: Equilateral Triangles Corollary to the Base Angles Theorem: If a Triangle is equilateral, then it is equiangular. Why must this be true? Corollary to the Converse Base Angles Theorem: If a Triangle is equiangular, then it is equilateral.

9. Homework 4.7 p.267 # 1,3,6,9,12,15,18,21