Reflexive property - identical angles, lines, etc are congruent to each other.

Transitive Property - congruency “transfers”

if ∠A ≅ ∠P and ∠P ≅ ∠T then ∠A ≅ ∠T

pythagorean theorem

isosceles triangle theorem

3rd angle theorem

The Third Angle Theorem states that if two angles in one triangle are congruent to two angles in another triangle, then the third pair of angles must also be congruent

∠C and ∠J are congruent because all the others are congruent.

Why? - because all triangles have to add up to 180°.

Transversal Properties

If two parallel lines are cut by a transversal, then:

1. corresponding angles are congruent

2. alternate Angles are congruent

3. alternate exterior angles are congruent

4. same side interior angles are complementary

1. angles B₁ and S₁ are congruent

2. angles B₁ and S are congruent

Vertical Angles are always congruent

Definition of an angle bisector

Definition of a segment bisector

Definition of a midpoint

Definition of perpendicular lines