It slightly obscures the simplicity of spread to define it in terms of angles and transcendental functions. It can instead be defined directly, as opposite/hypo

It slightly obscures the simplicity of spread to define it in terms of angles and transcendental functions. It can instead be defined directly, as opposite/hypotenuse on a right-angled triangle. Likewise, we can take quadrance as primary; and, if we're so inclined, we can define distance as its square root.