4-6 Isosceles and Equilateral Triangles Ms. Andrejko
Jan 29, 2016
4-6 Isosceles and Equilateral TrianglesMs. Andrejko
Real World
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
Theorems/Corollaries
•T 4.10- If 2 sides of a triangle are congruent, then the angles opposite those sides are congruent
•T 4.11- if 2 angles of a triangle are congruent then the sides opposite those angles are congruent
•C 4.3- A triangle is equilateral if and only if it is equiangular
•C 4.4- Each angle of an equilateral triangle measures 60°.
Examples
Practice
Examples
Refer to the figure•1. If AC ≅ AD, name two congruent
angles.
•2. If BE ≅ BC, name two congruent angles.
Practice
Refer to the figure•3. If ∠EBA ≅ ∠EAB, name two congruent
segments.
•4. If ∠CED ≅ ∠CDE, name two congruent segments.
Example/Practice1. m∠KML
2. m∠HMG
3. m∠GHM
4. If m∠HJM = 145, find m∠MHJ.
5. If m∠G = 67, find m∠GHM.
Example
Practice
Mixed Review
110
70
30
Mixed Review
12.
50
AAS or ASA
Mixed Review
20
90
40