1. Warm Up [On back counter]

2. Properties of Special Triangles
Objective:
To use and apply properties of isosceles and equilateral triangles

3. Isosceles Triangle
Vertex angle
legs
base
Base angles

4. Isosceles Triangle Theorem
If you were to construct an Isosceles Triangle you would:
Draw an angle, label it C
Mark congruent segments along each side. Label A and B
Connect A and B
Measure and label base angles.
Is there a pattern? A B
Base angles
Isosceles Triangle Theorem
If two sides of a triangle are congruent, then the angles opposite those sides are ________
congruent.

5. Does this theorem apply to an equilateral triangle?
The Isosceles Triangle Theorem applies to equilateral triangles.

7. Example Find the following: 3cm 69 69 A 7cm E 3 cm 960 420 420 3 cm CB D
Find the following: 69 69
3cm

8. Isosceles Triangle Theorem
Find x.