Definitions
Theorems
Postulates/More Definitions
Properties
Statements/Laws
100

Midpoint

a point that divides a segment into 2 CONGRUENT segments 

100

Vertical Angles Theorem 

If two angles are vertical then they are CONGRUENT

100

Segment Addition Postulate 

If C is between A and B then AC + BC = AB

100

Symmetric Property 

a=b then b=a


100

Law of Detachment 

if "p" then "q"

"p"

therefore "q"

200

Segment Bisector 

a point, line, segment, or ray that intersects a segment at the midpoint. 


200

Right Angle Congruence Theorem

 All right angles are congruent 

200

Angle Addition Postulate 

m<ABC +m<CBD =m<ABD

two parts of one angle add up to the whole angle. 


200

Transitive Property

a=b and b=c, then a=c 
200

Law of Syllogism 

If "p" then "q"

If "q" then "r" 

therefore If "p" then "r"

300

Vertical Angles

2 angles whose sides form opposite rays 


300

Congruent Supplements Theorem

If two angles are supplementary to the same angle then they are congruent 

300

Linear Pair Postulate 

if two angles form a linear pair then they are supplementary

300

Addition Property of Equality 

if a=b then a+c=b+c


300

Law of Contrapositive 

If "p" then "q"

~ q

therefore ~ p 

400

Complementary Angles 

2 angles that sum to 90 degrees

400

Congruent Complements Theorem

If two angles are complementary to the same angle then the two angles are congruent 

400

Linear Pair

2 angles that are adjacent and supplementary 

400

Property of Congruence 

congruent segments are equal in length. 

congruent angles are equal in degree.

400

Equivalence Statements 

Statements with the same truth value 

i.e. 

Conditional - Contrapositive 

Converse - Inverse

500

Supplementary Angles 

2 angles that sum to 180 degrees


500

Angle Bisector 

a ray that divides an angle into 2 congruent angles

500

Biconditional Statement 

a logical statement that is written as p if and only if q

both conditional and converse must be true. 

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