the affine plane
P through three draggable points.
the affine line
L through two draggable points.
their intersection
point (when it exists).
Drag any ● or
● to reshape the plane / line.
The line is parallel to the plane when its direction lies inside the
plane's direction space — then there is no intersection (or the whole line
lies in the plane).
Drag the background to orbit · scroll to zoom · axes labelled x, y, z.