When parallel lines are cut by a transversal line, the alternate angles formed are equal, the corresponding angles formed are equal, and the co-interior angles formed are supplementary. These relationships can be used to find missing angle measures, as when parallel train tracks are crossed by a road, the angles made at the intersection follow these rules.

1. RELATIONSHIPS
AMONG ANGLES
FORMED BY
PARALLEL
LINES
CUT BY A
TRANSVERSAL
LINE

4. a. The alternate angles formed are
______________________
c
b
g
f
a
d
e
h
1. Complete: When a transversal
meets two or more parallel lines:
equal

5. b. The co-interior angles formed are
______________________
1. Complete: When a transversal
meets two or more parallel lines:
c
b
g
f
a
d
e
h
supplementary

6. c. The corresponding angles formed are
______________________
c
b
g
f
a
d
e
h
1. Complete: When a transversal
meets two or more parallel lines:
equal

7. c. The corresponding angles
formed are equal.
c
b
g
f
a
d
e
h
b. The co-interior angles
formed are supplementary.
a. The alternate angles
formed are equal.

8. 2. In the following diagrams, 𝐴B||𝐶F. In each
case, find the value of 𝑎, giving a reason or
reasons.
Answer: a = 110 (corresponding angles)

9. 2. In the following
diagrams, 𝐴B||𝐶F.
In each case, find
the value of 𝑎,
giving a reason or
reasons.
Answer: a = 95 (co-interior angles)

12. GIVE 1 REAL-LIFE SITUATION
THAT WE CAN USE THIS CONCEPT
PARALLEL LINES CUT BY A
TRANSVERSAL LINE