What is the missing reason in step 5? Given: AB intersects DĖ at point C.
Prove: ZDCB ZECA
linear pair postulate
given
definition of complementary angles
congruent complements theorem
AX
2
B
E
Statements
Reasons
1.
AB intersects DE at point C.
1. given
2 2DCB and ZBCE are a linear pair. 2. def. of lin pr.
3. UDCB is supp, to ZBCE. 3. linear pair post
4. ZBCE and ZECA are a linear pair. 4. def. of lin pr.
5. BCE is supp, to ZECA.
5. ?
6. DCB ZECA
6. Supp. thm