A point is symbolized by a dot and represents a specific
location. It has no sixe nor shape.
A line is defined as a line of points that extends infinitely in
two directions which is shown by the arrowheads. A line is defined
by two points on the line and has only one dimension.
A line segment is a part of a line that has two defined
endpoints. A line segment represents a collection of points inside
the endpoints and it is named by its endpoints.
A ray is a line that only has one defined endpoint and one side
that extends endlessly away from the endpoint. A ray is named by
its endpoint and by another point on the line.
The angle that is formed by two rays that have the same endpoint
is called the vertex. The vertex is measured in degrees and is
easiest measured by using a protractor.
You can measure angles by using a protractor.
Angles can be classified according to how big they are. A right
angle has a measure of 90° whereas an angle that measures between
0° and 90° is called an acute angle. An angle that measures between
90° and 180° is called an obtuse angle whereas a straight angle
measures 180°.
A flat surface without edges and boundaries is called a plane.
It extends infinitely in two dimensions and is named by three
points in the plane that are not on the same line e.g. xyz. An
example of a plane would be the coordinate plane.
Two lines that meet in a point are called intersecting lines
Two lines, that are in the same plane and that will never
intersect are called parallel lines
Lines (or rays) that are perpendicular are lines that intersect
in a right angle. The symbol for perpendicular is
Skew lines are lines that are not in the same plane.
Video lesson: Classify all angles