## 2.5 Algebraic ProofProof: an argument that uses logic, definitions, properties, and previously proven
statements to show that a conclusion is true. Geometric proof: use def, postulates, properties and theorems to get a conclusion Theorem: a statement that can be proven Linear pair theorem: if 2 angles form a linear pair, then they are supp. Right angle congruence theorem: all right angles are congruent Vertical angles theorem: vertical angles are congruent. If 2 congruent angles are supp, then each angle is a right angle. Angle add postulate: if S is the interior of <PQR, then m<PQS+m<SQR=m<PQR Segment add postualte: if B is between A and C, then AB+BC=AC addition property of = if a=b then a+c=a+c subtraction prop of = if a=b then a-c=b-cmultiplication prop of =if a=b then ac=bcdivision prop of =if a=b c does not =0 then a/c=b/creflexive prop of =a=asymmetric prop of =if a=b then b=atransitive prop of =if a=b and b=c then a=csubstitution prop of =if a=b then be can be substi. for a in any expression |