11. Lines l and m are parallel.
l||m
120°
l
m
120°
120°
120°
Note the 4
angles that
measure 120°.
n
Line n is a transversal.
12. Lines l and m are parallel.
l||m
60°
l
m
60°
60°
60°
Note the 4
angles that
measure 60°.
n
Line n is a transversal.
13. Lines l and m are parallel.
l||m
60°
l
m
60°
60°
60°
There are many
pairs of angles that
are supplementary.
There are 4 pairs of
angles that are
vertical.
120°
120°
120°
120°
n
Line n is a transversal.
14. If two lines are intersected by a transversal
and any of the angle pairs shown below are
congruent, then the lines are parallel. This
fact is used in the construction of parallel
lines.
32. 9) Lines l and m are parallel.
l||m
Find the missing angles.
42°
l
m
b°
d°
f°
a °
c°
e°
g°
33. 9) Lines l and m are parallel.
l||m
Find the missing angles.
42°
l
m
42°
42°
42°
138°
138°
138°
138°
34. 10) Lines l and m are parallel.
l||m
Find the missing angles.
81°
l
m
b°
d°
f°
a °
c°
e°
g°
35. 10) Lines l and m are parallel.
l||m
Find the missing angles.
81°
l
m
81°
81°
81°
99°
99°
99°
99°
36. 11) Find the missing angles.
70 °
b°
70 °
d ° 65 °
Hint: The 3 angles in a
triangle sum to 180°.
37. 11) Find the missing angles.
70 °
40°
70 °
75 ° 65 °
Hint: The 3 angles in a
triangle sum to 180°.
38. 12) Find the missing angles.
45 °
b°
50 °
d ° 75 °
Hint: The 3 angles in a
triangle sum to 180°.
39. 12) Find the missing angles.
45 °
85°
50 °
20° 75 °
Hint: The 3 angles in a
triangle sum to 180°.
40. In the figure a || b.
13. Name the angles congruent to ∠3.
14. Name all the angles supplementary to ∠6.
15. If m∠1 = 105° what is m∠3?
16. If m∠5 = 120° what is m∠2?
∠1, ∠5, ∠7
∠1, ∠3, ∠5, ∠7
105°
60°