In mathematics, orthogonality is the generalization of the geometric notion of perpendicularity. Whereas perpendicular is typically followed by to when relating two lines to one another (e.g., "line A is perpendicular to line B"),[1] orthogonal is commonly used without to (e.g., "orthogonal lines A and B").[2]
Orthogonality is also used with various meanings that are often weakly related or not related at all with the mathematical meanings.
- ^ "perpendicular". Merriam-Webster.com Dictionary. Merriam-Webster.
- ^ "orthogonal". Merriam-Webster.com Dictionary. Merriam-Webster.