1. Mrs. McConaughyGeometry1 Isosceles and Equilateral Triangles Objective: To use and apply properties of isosceles triangles

2. Mrs. McConaughyGeometry2 An isosceles triangle is a ______________________ _______________. The angle between the two sides of equal length is the __________ and the other two angles are the __________. The congruent sides are the ______. The side between the two base angles is the ______. VOCABULARY a triangle with at least vertex angle base angleslegs. base. two sides equal.

3. Mrs. McConaughyGeometry3 INVESTIGATION: Isosceles Triangles If a triangle is isosceles, then _________________________________. (ISOSCELES TRIANGLE CONJECTURE) If the base angles of a triangle are congruent, then the triangle is ________________. (CONVERSE OF THE ISOSCELES TRIANGLE CONJECTURE) BICONDITIONAL: ________________________________________

4. Mrs. McConaughyGeometry4 Equilateral Triangles An equilateral triangle is __________, and conversely, and equiangular triangle is __________. BICONDITIONAL STATEMENT: _____________________________ (EQUILATERAL TRIANGLE CONJECTURE) equiangular equilateral

5. Mrs. McConaughyGeometry5 EXAMPLES: x 50 Y 70 22 x

6. Mrs. McConaughyGeometry6 Homework Assignment Isosceles ∆ WS, plus text page 214: 13-15, 21-25.