1. In conclusion... Same shape, same size Same shape, different size
What makes two shapes congruent?
What makes two shapes similar, but not congruent?
Same shape, same size
Same shape, different size
All angles are equal All sides are equal
All angles are equal
Sides are proportionate

2. Triangles
Let Review

3. Properties of all triangles
Interior Angles
Exterior Angles
Always add to 180 degrees
Always add to 360 degrees

4. Classifying Triangles - by sides
Two Equal Sides (will also have two equal angles)
All Equal Sides (will also have all angles equal = 60 degrees) No Equal Sides (also no equal angles)
Isosceles
Equilateral
Scalene

5. Classifying Triangles - by angles
One angle 90 degrees
One angle greater than 90
All angles less than 90
Right Angle
Obtuse
Acute

6. Naming Triangles Each vertex is named using an uppercase letter.
Eg. ∠A means angle A
Each side is names using the lower-case letter that corresponds to its opposite angle.
*Sometimes the sides are named like a line segment.
Eg. side c could also be side AB

7. Naming Triangles
A triangle is named using the letters of each angle, in alphabetical order
Triangle ABC or
△ABC

8. Other Angle Properties
Opposite Angles
Opposite angles equal each other
Complementary Angles
Complementary Angles add to 180
A & C
D & B
A & B, B & C,
C & D, A & D

9. Other Angle Properties
Parallel Lines
F Patterns (Eg. d = h, c = g, e = a)
Z Patterns (Eg. c = e, d = f)
C Patterns (Eg. d + e = 180)

10. Can you solve all the puzzle?