Geometry- Unit 3: Parallel Lines

Opposite rays

Rays going In opposite directions, sharing a common endpoint

Collinear points

points that lie on the same line

Linear pairs

2 angles that are adjacent and supplementary

Adjacent angles

whenever 2 non overlapping angles share a common ray and a common vertex

Vertical angles

vertical angles are a pair of non-adjacent angles formed by 2intersecting lines.( congruent and share a common vertex)

Angle bisector

a ray that divides an angle into 2 equal parts

Corresponding angles

angles on the same side of the transversal and in the same position

Alternate interior angles

angles on opposite sides of the transversal inside

Alternate exterior angles

angles on opposite sides of the transversal and outside

consecutive interior angles

interior angles that are on the same side of the transversal and inside both lines

consecutive exterior angles

angles on the same side of the transversal and outside both lines

perpendicular

perpendicular lines form right angles

Properties of congruence

Reflexive, symmetric, transitive property

properties of equality

Addition, subtraction, multiplication, division, distributive, substitution, reflective, symmetric, transitive property

Vertical angles theorem

if 2 angles are vertical, then they are congruent

complement theorem

if 2 angles form a right angle, then they are complementary. Right angle → complementary

supplement theorem

If 2 angles form a linear pair, then they are supplementary. Linear pair → supplementary

congruent complements theorem

If angle A is complementary to angle B and angle C is complementary to angle B , then angle A is equal to angle C

congruent supplements theorem

if angle A is supplementary to angle B and angle C is supplementary to angle B , then angle A is equal to angle C