Line of Intersection of Two Planes Calculator

Find the direction vector of the line where two planes meet.

Direction x 1
Direction y -1
Direction z 1

Formula: direction = n₁ × n₂ (cross product of normals)

Step-by-step with your numbers:
1. Values used:
2. Plane 1 a = 1
3. Plane 1 b = 1
4. Plane 1 c = 0
5. Plane 2 a = 0
6. Plane 2 b = 1
7. Plane 2 c = 1
8.
9. Direction x = Plane 1 a x Plane 1 b = 1 x 1 = 1
10. Direction y = -1
11. Direction z = Plane 1 a x Plane 1 b = 1 x 1 = 1
Did we solve your problem today?

Two non-parallel planes meet along a line; this finds that line's direction.

The math behind it

The line of intersection runs along the cross product of the two planes' normal vectors (a, b, c). A zero vector means the planes are parallel.

Worked example

Planes x + y = d and y + z = d → direction (1, −1, 1).

FAQ

What if the direction is zero?

The planes are parallel and either never meet or are the same plane.