Chapter 2: Q12. (page 63)
Write the name or statement of the definition, postulate, or theorem that justifies the statement about the diagram.
If ∠4 is complementary to ∠5 and ∠6 is complementary to ∠5 then .
Short Answer
The name of the theorem which justifies the statement about the given diagram is Theorem of Congruence of Angles and Complementary Angles.