geometry - Convert a direction into an angle on our compass

I have a new position vector and old x and z coordinates and I need to determine the angle traveled. So far I am getting the slopes absolute value and then using that to generate an angle. Based on

Celestial compass sensor mimics the insect eye for navigation

Autodesk Civil 3D Help, Direction Control Dialog Box

Unit Circle Labeled With Special Angles And Values

How to Construct a 60 Degrees Angle Using Compass and Ruler

Degrees of Turn Compass Activity (teacher made) - Twinkl

Orientation (geometry) - Wikiwand

Unit 11 Section 3 : Bearings

S2 4 angle and directions

Solved 3. Suppose you are driving 14 miles/hour with a

Navigation - Radio, GPS, Sonar