Triangle Congruence

1. Classifying Triangles

1.1. Key Terms: Acute triangle, Equiangular triangle, Right triangle, Obtuse triangle ,Equilateral triangle, Isosceles triangle, Scalene triangle

1.2. Manufacturers use properties of triangles to calculate the material needed to make triangular objects

1.3. You can classify triangles by their angle measures and side length

2. Angle Relationships in Triangle

2.1. Key Terms: Auxilliary line, Corollary, Interior, Exterior, Interior angle, Exterior angle, Remote interior angle

2.2. Interior angle is formed by two sides of a triangle and the exterior angle is formed by one side of the triangle

2.3. Apply the theorems about exterior and interior angles of the triangle

3. Congruent Triangles

3.1. Key Terms: Corresponding angles, Corresponding sides, Congruent polygons

3.2. Geometric figures are congruent if they are the same size and shape

3.3. If the triangle has congruent sides or angles then the triangle is congruent

4. Triangle Congruence: SSS and SAS

4.1. Key Terms: Triangle rigidity, Included angle

4.2. Triangle rigidity gives you a shortcut for proving two triangles are congruent

4.3. SSS stands for side, side, side and SAS stands for side, angle, side

5. Triangle Congruence: ASA, AAS, and HL

5.1. Key Terms: Included side

5.2. Included side is the common side of 2 angles in a polygon

5.3. ASA, AAS, and HL are all used to prove that a triangle is congruent

6. Congruence and Transformations

6.1. Key Terms: Dilation, Isometry, Rigid transformation

6.2. A transformation is a change in position, shape, or size of a figure

6.3. Types of Transformations: Rotation, reflection, translation, and dilation

6.4. Translations, reflections, and rotations produce images that are congruent to their preimages