1. Geometry
Perpendicular and Parallel Lines
What will we learn today?
• identifying and naming perpendicular
and parallel lines

2. We are going to learn
about lines today!

3. Lines are everywhere.
On roads
On shopping
items

4. Perpendicular Lines
Definition:
Lines that are at right angles (90°) to
each other.

5. Perpendicular
It means at right angles (90°) to.
How do we label perpendicular lines?
We can draw a little box in the corner.
The little box drawn in the corner, means
"at right angles"

6. Try this out!
Can you see any right angle(s) in the figure?

7. Try this out!
Can you see any right angle(s) in the figure?

8. Try this out!
Can you see any right angle(s) in the figure?

9. Try this out!
Can you see any right angle(s) in the figure?

10. Try this out!
Can you see any right angle(s) in the figure?

11. Try this out!
Can you see any right angle(s) in the figure?
There are 4 right angles in a square.

12. Applying the concept learnt
Since there are 4 right angles in a square,
we can find perpendicular lines.
A B
D C
Let’s label the square for easy reference.
Remember to label in sequence.

13. Applying the concept learnt
Line AB is perpendicular to Line BC.
A B
C

14. Try this out!
Can you find any other pair(s) of perpendicular
lines in the figure?

15. Try this out!
Line BC is perpendicular to Line DC.
A B
D C

16. Try this out by yourself!
In total, there are 4 pairs of perpendicular lines.
A B
D C

17. Summary
Perpendicular Lines:
Lines that are at right angles (90°) to
each other.

18. Parallel Lines
Definition:
• Lines are parallel if they are always the
same distance apart and will never meet.
• They also point in the same direction.
In conclusion, parallel lines are
Always the same distance apart and never touching.

19. Try this out!

20. Try this out!
B
D F
Name the parallel lines.
A
C E

21. Try this out!
B
D F
Line AB is parallel to
Line CD.
A
C E

22. Try this out!
B
D F
Line AB // Line CD.
A We can use //
to represent
C E ‘is parallel to’.

23. Do you know?
B
D F
Line EF is not parallel to
any of the lines.
A
C E

24. Explanation
B
F
Line EF is not parallel to
any of the lines.
A
Parallel Lines
1. Always the same
E distance apart
2. Never touching.

25. Explanation
D F
Line EF is not parallel to
any of the lines.
Parallel Lines
1. Always the same
C E distance apart
2. Never touching.

26. Try this out!
Can you see any parallel line(s) in the figure?

27. Try this out!
Can you see any parallel line(s) in the figure?
A B
D C
Let’s label the square for easy reference.
Remember to label in sequence.

28. Try this out!
Can you see any parallel line(s) in the figure?
A B
D C
Line AB // Line DC

29. Try this out!
Can you see any parallel line(s) in the figure?
A B
D C
Line AD // Line BC

30. Try this out!
Can you see any parallel line(s) in the figure?
There are 2 pairs of parallel lines.
A B
D C

31. Are you ready to
try out the
questions?

32. Visit kungfumath.sg today!