This interactive animation illustrates the concept
of the dot product of two vectors. The red vector is
"dotted" in to the green vector, and the scalar
result is represented by the length of the red highlight
along the green vector. The arc traced out by the red
vector represents the angle between the two vectors,
and the transparent green vector represents the negative
of the solid green vector.
The length and direction of the red vector can be changed
by using the arrow keys.