What is the formula for horizontal direction?

The formula for horizontal direction can be represented using the angle of elevation or azimuth in trigonometry. In a Cartesian coordinate system, the horizontal direction can be expressed as an angle θ relative to the positive x-axis, where the coordinates (x, y) can be used to determine the angle with tan(θ) = y/x. For navigation or compass directions, angles are typically measured clockwise from the north (0°) or east (90°).