AngleVector

AngleVector[θ] gives the list representing the 2D unit vector at angle θ relative to the x axis.

AngleVector[{r, θ}] gives the list representing the 2D vector of length r at angle θ.

AngleVector[{x, y}, θ] gives the result of starting from the point {x,y}, then going a unit distance at angle θ.

Examples

Get a unit vector at 45 degrees:

AngleVector[Pi/4]
(* {1/Sqrt[2], 1/Sqrt[2]} *)

Create a vector of specific length:

AngleVector[{3, Pi/6}]
(* {3 Sqrt[3]/2, 3/2} *)

Please visit the official Wolfram Language Reference for more details.