Points, Lines, and Planes

Points, lines, and planes as seen in a sidewalk

The following links hop to videos that present several fundamental Euclidean geometry concepts regarding points, lines, and planes.

Points

Symbol for a point

Symbol for a point

Lines

Symbols for lines and points

Symbol for a line

Multiple names for a line, collinear points

Noncollinear points

Lines not explicitly drawn

Lines plainly drawn

Rays

Symbols for rays

Symbol for a ray

Line segments

Symbol for a line segment

Symbol for a line segment

Planes

Symbol for a plane

Symbol for a plane

Three noncollinear points determine a plane

A plane can not be determined by two points

A plane can not be determined by collinear points

Intersections

Symbols for two lines intersecting

When two lines intersect, they usually intersect at a point

Two lines that do not intersect

When two planes intersect they intersect at a line