\documentclass[12pt]{article}
% % Tikz
\usepackage{tikz}

\begin{document}

\begin{tikzpicture}[scale=2]
  \begin{scope} [x={(-110:0.7cm)},y={(0:1cm)},z={(0,1cm)}]
    % la droite d' traversant le plan P
    \draw[thick] (-0.9,0.2,1)--(0.1,-0.5,-1) node [right]{$d'$};
    % le plan P
    \draw[fill=gray!30,opacity=0.8] (1,1,0)--(1,-1,0)--(-1,-1,0)--(-1,1,0)--cycle;
    \draw[line width=1.5pt](-1,1,0)--(1,1,0)--(1,-1,0);
    \draw (0.8,-0.8,0) node[xslant=0.1]{$P$};
    % la droite d dans le plan P
    \draw (0.3,-0.8,0)--(0,0.8,0) node[above]{$d$};
    % retracer la partie visible de la droite d' traversant le plan P
    \draw[thick] (-0.9,0.2,1)--(-0.4,-0.15,0) coordinate(A);
    % le point A
    \draw[fill=black] (A) circle(1pt) node [right]{$A$};
  \end{scope}
\end{tikzpicture}

\end{document}
