1. TRIANGLES CLASSIFICATIONS, ANGLES AND MORE!! 12/24/2015

2. Name a triangle with its 3 corner points (verticies) ABC, or BCA, or CAB… A BC

3. Classify 2 ways: by its sides and its angles

4. Classifying Triangles by Their Sides EQUILATERAL – 3 congruent sides EQUILATERAL – 3 congruent sides ISOSCELES –two sides congruent ISOSCELES –two sides congruent SCALENE – no sides congruent SCALENE – no sides congruent EQUILATERAL ISOSCELES SCALENE Works with Angles Matching TOO! 3 matching angles also! 2 matching angles also! No matching angles!

5. Classifying Triangles by Their Angles EQUIANGULAR – all angles are congruent EQUIANGULAR – all angles are congruent ACUTE – all angles are acute ACUTE – all angles are acute RIGHT – one right angle RIGHT – one right angle OBTUSE – one obtuse angle OBTUSE – one obtuse angle EQUIANGULAR ACUTE RIGHT OBTUSE 60º 70º 50º 40º 30º 120º 30º

6. Can You Classify the Different Triangles in the Picture Below?  ACD Obtuse, Scalene  ABC Equilateral, Equiangular  ECD Right, Scalene  ACE Scalene, Right So how did you do? So how did you do?

7. Classify the triangles by their sides: 60 ° 45 ° 70 ° 50 ° 45 °

8. ACT Practice AB C 10 6.32 10 Classify ABC a.scalene b.isosceles c.Equilateral d.right

9. Interior Angles of Triangles have a SUM of 180º 180º

11. xx 65 ° 75° y z

13. 20º 65º 10º ON THE TEST! 65º 10º 20º

14. 49º67º 3x + 99 = 180 X z 55 y z 64 + x+40 + 2x-5 = 180 - 99 = -99 3x = 81 x = 2727 55 Change notes to 55

18. Find x and all of the angles. (100 - 2x)º 3xº 5xº

19. Stop for now

20. Isosceles Triangles

21. 2 sides 2 angles BASE is not always at the bottom!!!! Isosceles Triangles Vertex

22. WARNING: Triangles may not be drawn the correct size. Trust the numbers and/or hatch marks. 15 50 ° W ° W°W°

23. p.34 60º 4x-20 w W=

24. Altitude of an Isosceles Triangle The BASE and VERTEX angle will be BISECTED. The BASE and VERTEX angle will be BISECTED. If the altitude runs from the vertex angle to the base side, it will always be perpendicular (90º) to the base. If the altitude runs from the vertex angle to the base side, it will always be perpendicular (90º) to the base.

26. Ready?