**Angle Between two Vectors**

Consider the two non zero vectors a and b , and let theta be the angle between the two vectors, then the angel between the two vectors formula can be derived from the dot product formula,

a . b = |a| |b| cos(theta)

so cosine of angle between two vectors a and b is

cos(theta) = ( a . b ) / (|a| |b|)

theta = arc cos[ (a.b)/ (|a| |b|)

**Interactive Graph : 1**

Use the Interactive diagram given below to see the angle between vectors in three dimensional view.

- Go Back to Default View: You may move the coordinate system back to the default view.
- Start / Stop rotating the View Automatically
- Adjust the View Direction: You may choose between the view towards the
*xOy*-plane,*xOz*-plane,*yOz*-plane, - rotate back to the default view.