Lesson 18A Properties for Proofs

Front

What is the difference between a theorem and a postulate?

Back

A postulate is a statement that is assumed true without proof while a theorem is a true statement that can be proven.

Front

Complete the statement using the subtraction property: If LM=XY then LM-TY=_____

Back

XY-TY

Front

What is a point that is in the exact middle of a segment?

Back

Definition of Midpoint

Front

Name the Property that the statement illustrates: If AB=21 and DC=21 then AB=DC

Back

Transitive Property

Front

What does a proof always start with?

Back

Given Statement(s)

Front

What is a postulate?

Back

A statement that is assumed true without proof.

Front

What is a theorem?

Back

A true statement that can be proven.

Front

What is the Reflexive Property?

Back

A property stating that any quantity is equal to itself (e.g., AB = AB).

Front

What is the Symmetric Property?

Back

If one quantity equals a second quantity, then the second quantity equals the first (e.g., if AB = CD, then CD = AB).

Front

What is the Transitive Property?

Back

If one quantity equals a second quantity, and the second quantity equals a third, then the first quantity equals the third (e.g., if AB = CD and CD = EF, then AB = EF).