Let $\mathbf{u,v,w}$ be vectors in $\mathbb{R}^3$. Suppose a vector $\mathbf{x} \in \mathbb{R}^3$ has coordinates $(x_1,x_2,x_3)$ in the basis {$\mathbf{u,v,w}$}. What is the formula for the length of $\mathbf{x}$ in terms of its coordinates and properties of $\mathbf{u,v,w}$?
For context, I'm a first year uni student.
Any hints/suggestions would be greatly appreciated!