1. Honors Geometry Section 4.4 Isosceles Triangle Theorem

2. Goals for today: 1. Identify the parts of an isosceles triangle. 2
Goals for today: 1. Identify the parts of an isosceles triangle. 2. Learn and apply the Isosceles Triangle Theorem and its converse. 3. Learn how we use the definition of an isosceles triangle, the ITT and its converse in proofs.

3. Recall that an isosceles is a triangle with _________________
Recall that an isosceles is a triangle with _________________. The congruent sides are called the ____ and the noncongruent side is called the_____. The angle formed by the two legs is called the ___________ while the two angles at each end of the base are called ___________.
two congruent sides
legs
base
vertex angle
base angles

4. Theorem Isosceles Triangle Theorem (ITT) If two sides of a triangle are congruent, then the angles opposite those sides are congruent.

5. Theorem Converse of the Isosceles Triangle Theorem (ITTC) If two angles of a triangle are congruent, then the sides opposite those angles are congruent.

6. Examples: Solve for x.