Definition:Orthogonal Basis of Vector Space

Definition
Let $V$ be a vector space.

Let $\BB = \tuple {\mathbf e_1, \mathbf e_2, \ldots, \mathbf e_n}$ be a basis of $V$.

Then $\BB$ is an orthogonal basis $\mathbf e_1, \mathbf e_2, \ldots, \mathbf e_n$ are pairwise perpendicular.