Properties of Congruence for Angles and Segments
Previously we looked at the Properties of Equality, which applied to numbers. The
Properties of Congruence are similar are similar to the Properties of Equality,
except that the Properties of Congruence apply to Angles and Segments.
Using the word bank at the bottom of the page (and your Properties of Equality for
Real Numbers sheet), decide which property is being described.
Every angle is equal to itself (e.g.,  A   A ).
If two angles are equal, you can write that equality
“either way” (e.g., if  A   B, then  B   A ).
If  A   B, then
 A +  B   B +  C and  A –  C   B -  C
If  A   B, then  A may be replaced by  B in any
equation or expression.
If  A   B, and  B   C, then  A   C.
Every segment is equal to itself (e.g., JK  JK ).
If two segments are equal, you can write that equality
“either way” (e.g., if JK  LM, then LM  JK ).
If JK  LM, then JK + XY  LM + XY, and
JK - XY  LM - XY
If JK  LM then JK may be replaced by LM in any
equation or expression.
If JK  LM, and LM  BC , then JK  BC
Word Bank:
 Transitive Property
 Reflexive Property
 Symmetric Property
 Substitution Property
 Addition/Subtraction Properties