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

70° 110° 70° 110° A B C D E F P Q
Figure (a)
55° 125° 70° 130° A B C D E F P Q
Figure (b)
75° 110° 45° 135° 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 = 70° ∠PQD = 70° ∠BPQ = 110° ∠PQC = 110° Alternate angles are Equal Lines are Parallel
(b) ∠APQ = 55° ∠PQD = 70° ∠BPQ = 125° ∠PQC = 130° Alternate angles are not Equal Lines are not Parallel
(c) ∠APQ = 75° ∠PQD = 45° ∠BPQ = 110° ∠PQC = 135° Alternate angles are not Equal Lines are not Parallel