A straight line
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A line.
raylineA straight line with no defined end points
A plane is 2-dimensional, and has infinite extent in any direction.
An infinite number of points extending in opposite directions with only one dimension describes a line. In geometry, a line is defined as a straight, one-dimensional figure that has no thickness and extends infinitely in both directions. It is characterized by having length but no width or depth, making it purely one-dimensional. Each point on the line represents a unique location along its infinite length.
A line is one dimensional and can have infinite length.
fg
A line.
Line and Ray APEX
raylineA straight line with no defined end points
There are two two-dimensional figure with an infinite length. They are rays, and lines.
a ray and a line
A plane is 2-dimensional, and has infinite extent in any direction.
An infinite number of points extending in opposite directions with only one dimension describes a line. In geometry, a line is defined as a straight, one-dimensional figure that has no thickness and extends infinitely in both directions. It is characterized by having length but no width or depth, making it purely one-dimensional. Each point on the line represents a unique location along its infinite length.
One-dimensional objects with infinite length include lines and line segments that extend indefinitely in both directions. In mathematics, a line is defined as having length without width or depth and continues infinitely. Other examples include curves like straight lines in geometry. However, line segments, by definition, have finite lengths and do not fit this criterion.
Infinite! Millimeters are a measure of length and are therefor 2 dimensional. Litre are a measure of volume and are 3 dimensional. Since millimetres have no volume you can stack as many of them as you like in a litre.
How about the number line