1.	Which statement explains why
		A.	Vertical angles are congruent.
		B.	All right angles are congruent.
		C.	Angles complementary to the same angle or to congruent angles are congruent.
		D.	Angles adjacent to the same angle or to congruent angles are congruent.
		Hint
	2.	In the figure shown, is complementary to and is complementary to . Which statement is true if none of the measures of the angles equal 45?
		A.	is complementary to itself.	B.
		C.		D.	is complementary to .
		Hint
	3.	If and are vertical angles and and find
		A.	72	B.	68
		C.	23	D.	43
		Hint
	4.	Which statement explains why
		A.	If the sum of the measures of two angles is 180, then they are supplementary.
		B.	All right angles are congruent.
		C.	If two angles form a linear pair, then they are supplementary.
		D.	Angles supplementary to the same angle are congruent.
		Hint
	5.	If and form a linear pair and m = 72, find m.
		A.	108	B.	18
		C.	72	D.	144
		Hint