Definição

1. Dois pontos, [; \underline{\textbf{p}}_1, \underline{\textbf{p}}_2 ;]
2. Ponto, [; \underline{\textbf{p}}_1,;] e Vetor Direcional, [; \underline{\textbf{v}}: ;]

   [; \underline{\textbf{v}}=\underline{\textbf{p}}_2- \underline{\textbf{p}}_1 ;]

Equação

[; ax+by=c ;]

[; \underline{\textbf{n}}=\widehat{\underline{\textbf{v}}} = \begin{pmatrix} a\\b \end{pmatrix} ;]

Parametrização

[; \underline{\textbf{r}}(t) = \underline{\textbf{p}}_1+t \underline{\textbf{v}} = \begin{pmatrix} x_1\\y_1 \end{pmatrix} + t\begin{pmatrix} v_1 \\v_2 \end{pmatrix}, \quad t \in \mathbb{R} ;]