3: Vectors in Three Dimensions Last updated Save as PDF Page ID 125034 3.1: Three Dimensional Vectors 3.2: Magnitude and Direction Cosines of a Vector 3.3: Arithmetic on Vectors in 3-Dimensional Space 3.4: The Unit Vector in 3-Dimensions and Vectors in Standard Position 3.5: The Dot Product, Length of a Vector, and the Angle between Two Vectors in Three Dimensions 3.6: The Cross Product- Algebra 3.7: The Cross Product- Geometry