1.	If and are vertical angles and and find
		A.	68	B.	43
		C.	23	D.	72
		Hint
	2.	Which statement explains why
		A.	If two angles form a linear pair, then they are supplementary.
		B.	Angles supplementary to the same angle are congruent.
		C.	All right angles are congruent.
		D.	If the sum of the measures of two angles is 180, then they are supplementary.
		Hint
	3.	Two angles are congruent if they are ______.
		A.	supplementary	B.	a linear pair
		C.	adjacent	D.	vertical
		Hint
	4.	In the picture, and are vertical. If then what is
		A.	90	B.	28
		C.	162	D.	81
		Hint
	5.	If and form a linear pair and m = 72, find m.
		A.	72	B.	18
		C.	144	D.	108
		Hint