1. Parallel and intersecting lines

2. Lines L1 and L2 are parallel lines.
Two lines that go on foreover on either side without meeting each other are called parallel lines.
Lines L1 and L2 are parallel lines.
Lines L3 and L4 are parallel lines.
Lines L5 and L6 are parallel lines. L1 L2 L3 L4 L5 L6

3. The lines L1 and l2 may look parallel, but they are not parallel.
When we extend the lines on one side the lines meet at a point.

4. The point they meet is called as point of intersection.
Two lines that go on to meet at some point are called as intersecting lines.
The point they meet is called as point of intersection. L1 L2 o L4 L3 N
Line L1 and L2 are intersecting lines
O is the point of intersection
Line L3 and L4 are intersecting lines
N is the point of intersection

5. When two lines intersect at right angles (900), then the intersecting lines are called as perpendicular lines. L1 L2 P L3 L4 Q
Line L1 and L2 are perpendicular lines
P is the point of intersection
Line L2 and L3 are perpendicular lines
Q is the point of intersection

6. Line P and Line Q are parallel lines
Example : Identify parallel , intersecting and perpendicular lines from the figure P Q X Y A B C D
Line P and Line Q are parallel lines
Line Y and Line P are intersecting lines
D is the point of intersection
Line Y and Line Q are intersecting lines
C is the point of intersection
Line X and Line P are perpendicular lines
B is the point of intersection
Line X and Line Q are perpendicular lines
A is the point of intersection

7. Just like parallel lines and intersecting line we can also have parallel line segments and intersecting line segments. A B Q P
The line segment AB
and PQ
are parallel line segments. X Y V U O
The line segment
O is the point of intersection. UV
and XY
are intersecting line segments.

8. Similarly we can also have parallel rays and intersecting rays.X Y M L
The line segment XY
and LM
are parallel rays. D C B A X
The line segment
X is the point of intersection. AB
and CD
are intersecting rays.

9. Try these
Identify parallel , intersecting and perpendicular lines from the figure