Finding the inverse of a m x m matrix whose columns are a set of non-zero, orthogonal vectors.

Question

Suppose that P is an $m \times m$ natrix whose columns are non-zero vectors $\boldsymbol{v_1},..,\boldsymbol{v_m}$. Also,$\{\boldsymbol{v_1},..,\boldsymbol{v_m}\}$ is an orthogonal set of vectors in $\Bbb{R^m}$.

How do we find the inverse of P using dot products of vectors $\boldsymbol{v_1},..,\boldsymbol{v_m}$?