Download File

1. Differentiate intersecting,
parallel, and skew lines;
2. Classify pairs of angles generated
whenever two lines are cut by a
transversal; and
3. Cite examples of parallel lines in
real life.
Are the horizontal lines parallel?
are planes that do not
intersect
M
N
are coplanar and do not
intersect
R
p
q
are not coplanar and do not
intersect
M
a
b
N
Theorem: If two parallel planes
are cut by a third plane, the lines
of intersection are parallel.
R A
S
B
P
D
C
a line that intersects two
coplanar lines in two different
points
c
2 1
a
34
6 5
b
7 8
c
21
a
34
65
b
7 8
Corresponding angles are two
nonadjacent angles on the same
side of the transversal such that
one is an exterior angle and the
other is an interior angle.
a
b
c
2 1
34
6 5
7 8
Interior angles: 3, 4, 5, and 6
Exterior angles: 1, 2, 7, and 8
c
21
a
34
65
b
7 8
Alternate interior angles are
two nonadjacent interior angles
on opposite sides of the
transversal.
3 & 5, 4 & 6
c
21
a
34
65
b
7 8
Alternate exterior angles are
two nonadjacent exterior angles
on opposite sides of the
transversal.
1 & 7, 2 & 8
Same-side interior angles
are two interior angles on the
same side of the transversal.
c
21
a
34
65
b
7 8
3 & 6, 4 & 5
Same-side Exterior angles
are two exterior angles on the
same side of the transversal.
c
21
a
34
65
b
7 8
1 & 8, 2 & 7
Try these
1 2
5 6
9 10
13 14
3 4
7 8
11 12
15 16
Identify each angle pair as alternate
interior, alternate exterior, same-side
interior, same-side exterior,
corresponding, or none of these.
1 2
5 6
9 10
13 14
1. 5 and 10
2. 6 and  7
3.  2 and  9
3 4
7 8
11 12
15 16
1 2
5 6
9 10
13 14
3 4
7 8
11 12
15 16
4.  9 and  11
5.  5 and  8
6.  1 and  14