Download Section 2.5

Bell Ringer
 What is the..
1.) Segment Addition Postulate
2.) Angle Addition Postulate
3.) Reflexive Property
Section 2.5
 Postulate or Axiom – Statement
that describes a fundamental
relationship between basic terms.
 Reflexive: a = a
 Symmetric: a = b then b = a
 Transitive: If a = b and b = c then
a =c
 Substitution: If a = b then a can
be replaced with b in any
equation
 Distributive: a(b + c) = ab + ac
Addition Property: a=b then a+c =
b+c
Subtraction property: a=b then a–c =
b-c
Multiplication Property: If a=b
then ac = bc
Division Property: If a=b then
a/c = b/c
Congruence of segments
is:
 Reflexive: AB = AB
 Symmetric: AB = BA
 Transitive: If AB = CD
and CD = EF
then AB =EF
Two- Column Proofs
Statement
Reason
Information
Given
Problem
Property
Theorem
Postulate
Definition
Axiom/Postulate
Example
Statement
Reason
3x – 2 = 4(x + 2)
Given
Paragraph Proof
Given AB is congruent to
BC prove that B is a
midpoint. We know that
B divides the segment AC
into two equal parts
because we are told that
AB is congruent to BC,
and the definition of
congruence is that they
are equal. B is a midpoint
because the definitions of
a mid point says that it is
a point that divides a
segment into two equal
parts.
2- Column
Statement
AB = BC
Reason
Class Work
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