ArcGIS Pro 2.7 API Reference Guide
CrossProduct Method
Example 

ArcGIS.Core.Geometry Namespace > Coordinate3D Structure : CrossProduct Method
The input Coordinate3D to use in the cross product.
Constructs the cross product of this Coordinate3D and another Coordinate3D. Vector cross product is used.
Syntax
public Coordinate3D CrossProduct( 
   Coordinate3D other
)
Public Function CrossProduct( _
   ByVal other As Coordinate3D _
) As Coordinate3D

Parameters

other
The input Coordinate3D to use in the cross product.

Return Value

A Coordinate3D representing the cross product of this Coordinate3D and the input Coordinate3D.
Remarks
Assume that the magnitude of this Coordinate3D > 0 and the magnitude of the input Coordinate3D > 0. Then the following statements are true:

If the cross product equals the Coordinate3D with magnitude = 0, then this Coordinate3D and the input Coordinate3D are parallel.

If the cross product equals a Coordinate3D with magnitude > 0, then the cross product is orthogonal to both this Coordinate3D and the input Coordinate3D.

Example
// Easy 3D vectors
Coordinate3D v = new Coordinate3D(0, 1, 0);
// v.Magnitude = 1

Coordinate3D other = new Coordinate3D(-1, 0, 0);
// other.Magnitude = -1

double dotProduct = v.DotProduct(other);      // dotProduct = 0

Coordinate3D crossProduct = v.CrossProduct(other);
// crossProduct.X = 0
// crossProduct.Y = 0
// crossProduct.Z = 1

Coordinate3D addVector = v.AddCoordinate3D(other);
// addVector.X = -1
// addVector.Y = 1
// addVector.Z = 0

// Rotate around x-axis
Coordinate3D w = v;
w.Rotate(Math.PI, other);
// w.X = 0
// w.Y = -1
// w.Z = 0

w.Scale(0.5);
// w.X = 0
// w.Y = -0.5
// w.Z = 0

w.Scale(-4);
// w.X = 0
// ww.Y = 2
// w.Z = 0
// w.Magnitude = 2

w.Move(3, 2, 0);
// w.X = 3
// w.Y = 4
// w.Z = 0
// w.Magnitude = 5
Requirements

Target Platforms: Windows 10, Windows 8.1

See Also

Reference

Coordinate3D Structure
Coordinate3D Members