3D Vector Cross Product and Parallelepiped Volume

3D Vector Cross Product and Parallelepiped Volume

Demonstrating that the volume of the parallelepiped formed by three vectors equals |a · (b × c)|

This 3D simulation shows how the volume of the parallelepiped formed by vectors a, b, and c equals the absolute value of the scalar triple product (a · (b × c)). Adjust the vectors to see how the volume changes while maintaining this mathematical relationship.

2
0
0
0
2
0
0
0
2
Cross Product b × c
(0, 0, 4)
Scalar Triple Product a·(b×c)
8.00
Parallelepiped Volume
8.00
|a·(b×c)|
Tetrahedron Volume
1.33
⅙|a·(b×c)|

Mathematical Proof

The volume of the parallelepiped formed by vectors a, b, and c equals the absolute value of the scalar triple product:

1. The cross product b × c gives a vector perpendicular to b and c with magnitude equal to the area of the parallelogram formed by b and c

2. The dot product a · (b × c) projects a onto this perpendicular vector, giving the "height"

3. The absolute value gives the volume of the parallelepiped

∴ Volume = |a · (b × c)|

The tetrahedron formed by the three vectors has 1/6th of this volume.

With a = (2, 0, 0), b = (0, 2, 0), c = (0, 0, 2), b × c = (4, 0, 0), a·(b×c) = 8, so volume = 8.

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