knowt logo

Geometry proofs vocab.

PROOF LIST (LIVE DOCUMENT) TO STUDY

Bi-Conditional “… if and only if …”

Implies “if… , then…”

Angle

m∠

Measure of Angle

Congruent

Parallel

Perpendicular

Addition Property of Equality

If a = b, then a + c = b + c

Subtraction Property of Equality

If a = b, then a – c = b – c

Multiplication Property of Equality

If a = b, then ac = bc

Division Property of Equality

If a = b and c ≠ 0, then

Substitution Property of Equality

If a = b, then a can be substituted for b in any equation or expression.

Distributive Property

a ( bc ) = ab + ac, where a, b, and c, are real numbers

Simplify

Combine like terms

Reflexive Property of Equality

a = a,   AB = AB, m∠ A = m∠ A

Reflexive Property of Congruence

A ≅ ∠ A

Symmetric Property of Equality

If a = b, then b = a , If AB = CD, then CD = AB,         If mA = mB, then mB = mA

Symmetric Property of Congruence

If , thenIf ∠ A ≅ ∠ B, then ∠ B ≅ ∠ A

Transitive Property of Equality

If a = b and b = c, then a = c,If AB = CD and CD = EF, then AB = *EF,*If mA = mB and mB = mC, then mA = mC

Transitive Property of Congruence

If a = b  and b = c , then a = c.If ∠ A ≅ ∠ B and ∠ B ≅ ∠ C, then ∠ A ≅ ∠ C

Substitution Property

If a = b, then a can be substituted for b.

Definitions

Congruent  - also equal in measure

Angle Bisector  - divides into two ≅ angle

Segment bisector - line, segment or ray that divides a segment at the midpoint

Midpoint – a point that divides a line segment into two ≅ segments

Supplementary angles - two angles that add up to 180˚

Complementary Angles - two angles that add up to 90˚

Linear Pair – pair of angles that are adjacent and supplementary

Right Angle – Angle measures exactly 90˚

Perpendicular - intersects at a right angle, creates a right angle

Vertical Angles - if vertical angles, then they are congruent

Postulates (assumed true without proof)

Segment Addition Postulate – If B is between AC on a line segment, then AB + BC = AC

Angle Addition Postulate – If T is in the interior of ∠ABC, then m∠ABT + m∠TBC = m∠ABC

Right Angle Congruence – all right angles are congruent

Theorems (statements that have been proven)

Congruent Complements Theorem - two angles complementary to the same angle or congruent angles are congruent

Congruent Supplements Theorem - two angles supplementary to the same angle or congruent angles are congruent

Geometry proofs vocab.

PROOF LIST (LIVE DOCUMENT) TO STUDY

Bi-Conditional “… if and only if …”

Implies “if… , then…”

Angle

m∠

Measure of Angle

Congruent

Parallel

Perpendicular

Addition Property of Equality

If a = b, then a + c = b + c

Subtraction Property of Equality

If a = b, then a – c = b – c

Multiplication Property of Equality

If a = b, then ac = bc

Division Property of Equality

If a = b and c ≠ 0, then

Substitution Property of Equality

If a = b, then a can be substituted for b in any equation or expression.

Distributive Property

a ( bc ) = ab + ac, where a, b, and c, are real numbers

Simplify

Combine like terms

Reflexive Property of Equality

a = a,   AB = AB, m∠ A = m∠ A

Reflexive Property of Congruence

A ≅ ∠ A

Symmetric Property of Equality

If a = b, then b = a , If AB = CD, then CD = AB,         If mA = mB, then mB = mA

Symmetric Property of Congruence

If , thenIf ∠ A ≅ ∠ B, then ∠ B ≅ ∠ A

Transitive Property of Equality

If a = b and b = c, then a = c,If AB = CD and CD = EF, then AB = *EF,*If mA = mB and mB = mC, then mA = mC

Transitive Property of Congruence

If a = b  and b = c , then a = c.If ∠ A ≅ ∠ B and ∠ B ≅ ∠ C, then ∠ A ≅ ∠ C

Substitution Property

If a = b, then a can be substituted for b.

Definitions

Congruent  - also equal in measure

Angle Bisector  - divides into two ≅ angle

Segment bisector - line, segment or ray that divides a segment at the midpoint

Midpoint – a point that divides a line segment into two ≅ segments

Supplementary angles - two angles that add up to 180˚

Complementary Angles - two angles that add up to 90˚

Linear Pair – pair of angles that are adjacent and supplementary

Right Angle – Angle measures exactly 90˚

Perpendicular - intersects at a right angle, creates a right angle

Vertical Angles - if vertical angles, then they are congruent

Postulates (assumed true without proof)

Segment Addition Postulate – If B is between AC on a line segment, then AB + BC = AC

Angle Addition Postulate – If T is in the interior of ∠ABC, then m∠ABT + m∠TBC = m∠ABC

Right Angle Congruence – all right angles are congruent

Theorems (statements that have been proven)

Congruent Complements Theorem - two angles complementary to the same angle or congruent angles are congruent

Congruent Supplements Theorem - two angles supplementary to the same angle or congruent angles are congruent

robot