1. 10/1/20154-6: Analyzing Congruent Triangles 4 – 6: Analyzing Isosceles Triangles Expectation: G1.2.2: Construct and justify arguments and solve multi-step problems involving side length, angle measure, perimeter and area of all types of triangles.

2. 10/1/20154-6: Analyzing Congruent Triangles Isosceles Triangles In an isosceles triangle, the 2 congruent sides are called the legs and the third side is called the base. Label the base and the legs on the triangle below. AB C

3. 10/1/20154-6: Analyzing Congruent Triangles Isosceles Triangles In an isosceles triangle, the 2 angles at the ends of the base are referred to as base angles and the angle where the legs meet is called the vertex angle. Label the base angles and the vertex angle on the triangle below. A B C

4. 10/1/20154-6: Analyzing Congruent Triangles Look at the isosceles triangles below. What appears to be true about the base angles?

5. 10/1/20154-6: Analyzing Congruent Triangles Isosceles Triangle Theorem If 2 sides of a triangle are congruent, then the angles opposite those sides are __________.

6. What is the measure of ∠ α in the diagram below? A.20° B.55° C.70° D.75° E.110° 10/1/20154-6: Analyzing Congruent Triangles 10 α 55°

7. 10/1/20154-6: Analyzing Congruent Triangles Triangle ABC is isosceles. Calculate the value of x. A C B 5x+2310x-7

8. 10/1/20154-6: Analyzing Congruent Triangles Given the information below, what can we conclude about AB and AD? A D C B

9. 10/1/20154-6: Analyzing Congruent Triangles Justify your claim!

10. 10/1/20154-6: Analyzing Congruent Triangles Isosceles Triangle Converse Theorem If 2 angles of a triangle are congruent, then the sides opposite those angles are ___________.

11. 10/1/20154-6: Analyzing Congruent Triangles Solve for x. 38 7x+12 12x-18

12. 10/1/20154-6: Analyzing Congruent Triangles Equilateral Triangle Corollary: A triangle is equilateral iff it is ________________. Equilateral Triangle Angle Corollary: Each angle of an equilateral triangle has measure of ____.

13. 10/1/20154-6: Analyzing Congruent Triangles Given: Triangle ABC is equilateral. Prove: ∠ A ≅∠ B ≅∠ C A C B

14. 10/1/20154-6: Analyzing Congruent Triangles If CF ≅ KF, name 2 congruent angles.

15. 10/1/20154-6: Analyzing Congruent Triangles If ∠ 10 ≅ ∠ DFL, name 2 congruent segments.

16. 10/1/20154-6: Analyzing Congruent Triangles If m ∠ 1 = 30°, determine the measures of the other numbered angles. 1 2 3 5 7 8 6 4

17. In ΔABC below, AB ≅ BC, and the measure of ∠ B is 55°. What is the measure of ∠ C? A.27.5° B.55° C.62.5° D.125° E.cannot be determined from the given information. 10/1/20154-6: Analyzing Congruent Triangles

18. 10/1/20154-6: Analyzing Congruent Triangles Assignment pages 225-227, #15, 21, 27-30(all), 36, 47