2D
Coordinate Geometry Calculator
Calculate points, lines, circles, triangles and polygons in a Cartesian coordinate system.
Distance & midpoint
All calculations are 2D, retain unrounded values and use a scale-aware tolerance. Polygon points must follow boundary order; self-intersections are rejected.
Result
Result
5
Coordinate Geometry Calculator
All calculations are 2D, retain unrounded values and use a scale-aware tolerance. Polygon points must follow boundary order; self-intersections are rejected.
Frequently asked questions
How are distance and midpoint calculated?
Using Δx and Δy: d = √(Δx²+Δy²); the midpoint averages both coordinates.
What happens for a vertical line?
It is shown as x = constant and in general form; no finite slope exists.
How are intersection, parallelism and perpendicularity determined?
A determinant distinguishes intersection from parallel or identical lines; a normal-vector dot product checks perpendicularity.
What is the foot of a perpendicular?
It is the closest point on the line.
How is a circle found through three points?
Three non-collinear points determine one circle through a determinant.
How are triangle and polygon areas calculated?
Triangle area follows directly from coordinates; polygon area uses the shoelace formula.
Why does point order matter?
Points are connected in boundary order and the last is closed to the first.
Are self-intersecting polygons supported?
No. Self-intersections are detected and rejected as a simple polygon.
Does the calculator support 3D?
No. This version is limited to two-dimensional coordinate geometry.