Distance between two points in the Cartesian plane is the length of the line segment joining them, found from the horizontal and vertical changes using the Pythagorean theorem: . The coordinates may produce exact radical or decimal lengths, and reversing the points leaves the distance unchanged; this treatment is limited to Euclidean distance in two dimensions, not three-dimensional or non-Euclidean settings.
The distance between two points is the length of the line segment connecting them. For points and , use the distance formula:
This formula uses the horizontal change, , and the vertical change, .
Example: Find the distance between and .
Identify the coordinates:
Substitute into the formula:
Simplify the differences:
Square and add:
Simplify:
The distance between and is units. Reversing the order of the points gives the same distance because the differences are squared.
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