Intro to Geometry Proofs Vocab

An angle with a measure equal to 90 degrees is called a __________________________.

• right angle

• obtuse angle

• acute angle

• congruent angle

An angle with a measure equal to 180 degrees is called a _____________________.

• straight angle

• line

• obtuse angle

• acute angle

Consists of 2 endpoints and all the points in between.

• Ray

• Line

• Line Segment

• Angle

Select the correct definition.

Vertical Angles

• a figure formed by two rays with a common endpoint.

• angles that share a ray.

• two angles that are opposite of each other and congruent.

• two angles that have a measure of 180 degrees.

What is the REASON for Statement #1?

• Given

• Definition of Complementary Angles

• Substitution Property

• Reflexive Property of Congruence

What is the correct reason for line 5 and 6?

• 5.Transitive Property of equality 6. Substitution

• 5.Algebra 6.Definition of ≅

• 5.Substitution 6.Definition of ≅

• 5.Angle addition postulate 6.Substitution

What is the reason?

• Definition of vertical angles

• Angle addition postulate

• Definition of angle bisectors

• Vertical angles are congruent

Select the definition, property, postulate or theorem that justifies the statement.

If m<1 + m<2 = 180 and m<2 +m<3 = 180, then <1≅<3.

• Transitive Property

• Definition of ≅ Angles

• Supplementary of Same Angles

• Definition of Complementary Angles

What is the correct statement for 3?

• AD=EA

• AB=CD

• AB≅EF

• AB=EF

What is the REASON for Statement #2?

• Given

• Definition of Complementary Angles

• Substitution Property

• Reflexive Property of ≅