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

60° 110° 70° 120° 120° 70° 70° 120° A B C D E F P Q
Figure (a)
75° 110° 65° 125° 110° 75° 65° 125° A B C D E F P Q
Figure (b)
55° 135° 30° 115° 135° 55° 30° 115° A B C D E F P Q
Figure (c)
Figure Pair I Pair II Result (relationship
between Co-interior angles)		 Lines are (Parallel/ Not Parallel)
∠APQ ∠PQC ∠APQ +
∠PQC		 ∠BPQ ∠PQD ∠BPQ +
∠PQD
(a) 60° 120° 180° 110° 70° 180° Co-interior angles are Supplementary Lines are Parallel
(b) 75° 125° 200° 110° 65° 175° Co-interior angles are not Supplementary Lines are not Parallel
(c) 55° 115° 170° 135° 30° 165° Co-interior angles are not Supplementary Lines are not Parallel