Definice. Vzdálenost dvou vektorů: $\rho (\overrightarrow{x},\overrightarrow{y})=\Vert \overrightarrow{x}-\overrightarrow{y}\Vert$

Definice. Vzdálenost dvou množin: $\rho (M,N)=\inf \left\{\rho (\overrightarrow{x},\overrightarrow{y})\right|\overrightarrow{x}\in M,\overrightarrow{y}\in N\}$

Definice. Úhel mezi přímkami: $\angle pq=\arccos \frac{{\displaystyle \left|⟨{\overrightarrow{s}}_p|{\overrightarrow{s}}_q⟩\right|}}{{\displaystyle \Vert {\overrightarrow{s}}_p\Vert \cdot \Vert {\overrightarrow{s}}_q\Vert }}$

Definice. Úhel mezi rovinami: $\angle \rho \sigma =\arccos \frac{{\displaystyle \left|⟨{\overrightarrow{n}}_{\rho }|{\overrightarrow{n}}_{\sigma }⟩\right|}}{{\displaystyle \Vert {\overrightarrow{n}}_{\rho }\Vert \cdot \Vert {\overrightarrow{n}}_{\sigma }\Vert }}$

Definice. Úhel mezi přímkou a rovinou: $\angle \rho \sigma =\arcsin \frac{{\displaystyle \left|⟨{\overrightarrow{s}}_p|{\overrightarrow{n}}_{\sigma }⟩\right|}}{{\displaystyle \Vert {\overrightarrow{s}}_p\Vert \cdot \Vert {\overrightarrow{n}}_{\sigma }\Vert }}$