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Vector Normal to a Plane

`V = f( "P1" , "P2" , "P3" )`
`(P1)"Point 1 Coordinates"`
`(P2)"Point 2 Coordinates"`
`(P3)"Point 3 Coordinates"`

The Unit Vector Normal to a Plane calculator computes the normal unit vector to a plane defined by three points in a three dimensional cartesian coordinate frame./attachments/394ac85b-6bc9-11eb-ba43-bc764e203090/P3.JPG

INSTRUCTIONS: Enter the following:

  • (P1) Point 1 (e.g. 2,3,4)
  • (P2) Point 2 (e.g. 5,6,7)
  • (P3) Point 3 (e.g. 1,8,9)

Normal Unit Vector to the Plane (V): The calculator returns the vector normal to the plane defined by the three points.

NOTE: Positions in 3D and vectors are entered via comma  separate strings  (e.g. 4,12,-2).

The Math / Science

To compute the normal vector to a plane created by three points:

  1. Create three vectors (A,B,C) from the origin to the three points (P1, P2, P3) respectively.
  2. Using vector subtraction, compute the vectors U = A - B and W = A - C
  3. Compute the vector cross product, V = U x W
  4. Compute the unit vector of V,  `hatV = vecV/(|vecV|)`  

`hatV` is the unit vector normal to the plane created by the three points.


3D Vector Functions