Relationship between the alternate angles formed when two lines are transversed by transversal

63° 117° 63° 117° A B C D E F P Q
Figure (a)
75° 105° 63° 117° A B C D E F P Q
Figure (b)
63° 117° 52° 128° A B C D E F P Q
Figure (c)
Figure Pair I Pair II Result (relationship
Between
Alternate angles)		 Lines are (Parallel / Not Parallel)
(a) ∠APQ = 63° ∠PQD = 63° ∠BPQ = 117° ∠PQC = 117° Alternate angles are Equal Lines are Parallel
(b) ∠APQ = 75° ∠PQD = 63° ∠BPQ = 105° ∠PQC = 117° Alternate angles are not Equal Lines are not Parallel
(c) ∠APQ = 63° ∠PQD = 52° ∠BPQ = 117° ∠PQC = 128° Alternate angles are not Equal Lines are not Parallel