POINT
A position on a paper or a position on space, no size
- Marked by upper case letter
A B
LINE
An infinite number of points
<—--------—---------------------—--------—--------------------->
A B
Arrows indicate the direction of the line
The arrows also show there's no eneding
The line can be called AB or BA
<—--------—---------------------—--------—--------------------->
If no point, line will be called line L
Collinear and Non-collinear
Collinear point: Points that lie on the same line
A B C
Non- Collinear point: Points that don’t lie on the same line
B
A C
PLANE: an infinite number of lines
Flat surface that extends in all directions
—-—-—-—-—-
| Q |
| E |
| F G |
—-—-—-—-—-
-plane Q
Plane FEG
Plane GEF
Coplanar point: Points that lie on the same plane
Line segments: section of line that has specified ends
•—-----------------------------• - endpoints
G H
GH or HG
Rays: A line that as fixed starting point, but no end point
•—-----------------------------•----------------------------> GH
G H
<—-----------------------------•----------------------------• HG
G H
Opposite rays: two rays that share the same initial point and extend infinitely in opposite directions along the same line.
If point 𝐶 lies on 𝐴𝐵 between 𝐴 and 𝐵, then 𝐶𝐴 and 𝐶𝐵 are opposite rays.
<—--------•—-------------------•--—--------—---------•------------>
A C B
INTERSECTION: One or more points laying on two or more geometric figured
An intersection of two distinct line is a point
An intersection of two distinct plane is a line