Lines A and B are parallel.
Find the measure of La.
A+
B+
a
107°
mza =
=
[ ? ] °

Answer:
From the figure, we understand that
∠
1
and
∠
3
together form a straight line.
Thus,
∠
1
+
∠
3
=
180
0
⇒
35
0
+
∠
3
=
180
0
⇒
∠
3
=
145
0
Now, since
l
and
m
are parallel lines cut by transversals
s
and
t
,
∠
3
an
∠
4
are corresponding angles.
We know that corresponding angles are equal. Thus
∠
4
=
∠
3
=
145
0
Similarly
∠
2
an
∠
4
are corresponding angles.
Thus
∠
2
=
∠
4
=
145
0