Different kinds of lines

1. GEOMETRY
Unit 3

2. How is a point related to the real world?
o A point is a dot on a specific location.
o A good example of a point in the real world would be an
eyeball of the eye.

3. This is called a point!
When it’s at the end of a line
it is called an endpoint!

4. POINT
● A POINT is an exact location on a graph, shape or in
“space”.
● The Hershey Kiss is a POINT on the line

5. How does a line relate to the real world?
o A line is straight and has no definite measure.
o A road would be an example of a line, because it is straight and
they do end but it could go on and on for a while.

6. How can a Collinear points relate to the real world?
o Collinear points are points that line on the same line.
o A stoplight would be a real world example because the
three lights are on the same line.

7. Collinear Points: Three or more points that lie on
the same line are called collinear points.
Collinear Points
Non-Collinear Points
Y Z X
Y
X
Z
We cannot connect all the points
in one line
We can connect all the points in
one line
Non-Collinear Points

8. Collinear or Not??
A, B, and C are
Collinear Points
E, F and G are
Non-Collinear Points
M, N and O are
Collinear Points
A
B
C
F
G
E
O
N
M

9. Line
A line goes on and on in both directions.
A line is drawn with an arrow on each end

10. Line: a straight path that goes in two
directions without ending.
A B
(AB) or (BA) Read: “Line AB”

11. How can a segment relate to the real world?
o A segment an actual measure, it is straight and it is a part of
a line.
o A crosswalk would be a good example, because it goes from
point a to point B.

12. Line Segment
A line segment is a part of a line. It is
drawn with two endpoints

13. ENDPOINT
● An ENDPOINT is a point at the end of line segment
or semi-straight line.
Endpoint

14. A line segment has two endpoints.
[EF] or [FE]
Read: “Line Segment EF”
E F

15. How can a Semi-Straight Line relate to the real world?
o A Semi-straight line only has one stopping point from the
beginning and has no definite measure
o A stop sign then a road would be a semi-straight line because at
the stop sign you are stopped then you keep going on the road

16. Semi-Straight Line
A Semi-straight line goes on and on in one
direction. It is drawn with an arrow on one end
and an endpoint on the other.

17. A Semi-Straight Line has one end point
and goes on forever in only one direction.
[CD) Read: “Semi-Straight Line [CD)”
C D

18. Identify the type of line:
straight line, semi-straight line, or line segment.

19. Identify the type of line:
straight line, semi-straight line, or line segment.

20. Identify the type of line:
straight line, semi-straight line, or line segment.

21. Identify the type of line:
straight line, semi-straight line, or line segment.

22. Identify the type of line:
straight line, semi-straight line, or line segment.

23. Identify the type of line:
straight line, semi-straight line, or line segment.

25. Midpoint
Oh look it is
in the middle!

26. A B
M
Is M the midpoint of [AB]?
Yes! M is in the middle, look carefully.
It divides the segment into 2 equal parts.

27. A B
M
Is M the midpoint of [AB]?
No! M is not in the middle, look carefully.
It does not divides the segment into 2 equal parts.

28. C D
N
Is N the midpoint of [CD]?
Yes! N is in the middle, look carefully.
It divides the segment into 2 equal parts.

29. C D
N
Is N the midpoint of [CD]?
Yes! N is in the middle, look carefully.
It divides the segment into 2 equal parts.

30. Draw MN = 8 cm
8 cm
M N
Using the ruler!
Start from 0
Done!
Find the midpoint L of [MN]
How??
Divide the segment into 2 equal parts
How??
_+_=8
Remember 2 EQUAL PARTS!

31. Draw MN = 8 cm
8 cm
M N
Using the ruler!
Done!
_+_=8
Remember 2 EQUAL PARTS!
Can I say 2+6=8?
No, they are not equal.. 2 ≠ 6
Mmmm, can I say 3+5?
No, they are not equal.. 3 ≠ 5

32. Draw MN = 8 cm
4 cm
M N
Using the ruler!
Start from 0
Done!
_+_=8
Remember 2 EQUAL PARTS!
Ohhh easy!!
So 4 + 4 = 8
Yesss 4=4!!
Horraayyyy!!
4 cm
8cm
L
Get your ruler again
and measure 4 cm
from point M, then
locate L the midpoint.
So, ML = 4 cm
& LN = 4 cm
So, ML = LN = 4 cm!

33. Draw AB = 10 cm
10 cm
A B
Using the ruler!
Start from 0
Done!
Find the midpoint K of [AB]
How??
_+_=10
Remember 2 EQUAL PARTS!
Okayyy, 5 + 5 = 10
AK = 5 cm, KB = 5 cm
Get your ruler again
and measure 5 cm
from point AK then
locate K the midpoint.
K
5 cm
5 cm

34. Locate the midpoint of each line Segment
G H
M
Remember it will be in the middle
and we will have 2 equal parts
__+__=14

36. Parallel lines are always the same distance
apart. They will never touch.
“Enemy Lines”
Parallel Lines

37. Can you find the parallel lines?

38. Intersecting Lines
Intersecting lines are two lines that cross
each other
“Friends”

39. Can you find the intersecting lines?

40. Perpendicular Lines
Perpendicular lines are
two lines that intersect
to form right angles.
90
“Married”

41. Can you find the perpendicular lines?

42. J K
L M
Parallel Lines- lines that never cross or become
further apart from each other.
(JK)║(LM)
Read: “Line (JK) is parallel to
line (LM)”

43. Intersecting Lines- lines that cross each other.
O
P
Q
R
(OP) intersects(QR)

44. Perpendicular Lines- lines that cross or meet each
other to form square corners (90º angle).
90º/Right
Angle
(ST) ┴ (UV)
S T
U
V Read: “Line (ST) is
perpendicular to line
(UV)”

45. Identify if the lines are parallel, perpendicular, or
intersecting (not at a perpendicular angle).

46. Identify if the lines are parallel, perpendicular, or
intersecting (not at a perpendicular angle).

47. Identify if the lines are parallel, perpendicular, or intersecting
(not at a perpendicular angle).

48. Identify if the lines are parallel, perpendicular, or intersecting
(not at a perpendicular angle).

49. Identify if the lines are parallel, perpendicular, or
intersecting (not at a perpendicular angle).

50. Identify if the lines are parallel, perpendicular, or intersecting
(not at a perpendicular angle).

51. Identify if the lines are parallel, perpendicular, or
intersecting (not at a perpendicular angle).

52. Perpendicular lines are also intersecting lines
because they cross each other.
Perpendicular lines are a special
kind of intersecting lines because
they always form “perfect” right
angles.
90

53. Name each figure
Point
Line
Semi-Straight Line
Line Segment
Perpendicular
Intersecting
Parallel

54. Alternative resources