Making the right angle mark on a right angle triangle?

Question

How do I add the 'right angle sign' at B?

\documentclass[12pt]{book} 
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}
 % Draw the triangle
        \draw[fill=gray!10]  (1, 0) coordinate (A) 
        -- node[left] {} (0,2) coordinate (C) 
        -- node[above right] {} (6,2) coordinate (B) 
        -- node[below] {}  (1, 0);
         %The right-angle mark at C is drawn.
% Draw nodes
        \node at (A)[anchor=north] {$B$};
        \node at (B)[anchor=north] {$C$};
        \node at (C)[anchor=south] {$A$};
      \end{tikzpicture}
\end{document}

Does this answer your question? Mark 90 degree angle in tikz in german convention or How to Mark Right Angle in Tikz — Roland, Jan 28 '21 at 00:52
omg tysm!! i figured out a harder way to do it but this is so much easier!!! <3 — selfproclaimedhustler, Jan 28 '21 at 01:17

score 0 · Answer 1 · answered Jan 28 '21 at 00:55

This I made according to the answer here

\documentclass[12pt]{book} 
\usepackage{tikz}
\newcommand*{\rechterWinkel}[3]{% #1 = point, #2 = start angle, #3 = radius
    \draw[shift={(#2:#3)}] (#1) arc[start angle=#2, delta angle=90, radius = #3];
    \fill[shift={(#2+45:#3/2)}] (#1) circle[radius=1.25\pgflinewidth];
}
\begin{document}
\begin{tikzpicture}
 % Draw the triangle
        \draw[fill=gray!10]  (1, 0) coordinate (A) 
        -- node[left] {} (0,2) coordinate (C) 
        -- node[above right] {} (6,2) coordinate (B) 
        -- node[below] {}  (1, 0);
         %The right-angle mark at C is drawn.
% Draw nodes
        \node at (A)[anchor=north] {$B$};
        \node at (B)[anchor=north] {$C$};
        \node at (C)[anchor=south] {$A$};
\rechterWinkel{0.85,0.04}{15}{.5}
  \end{tikzpicture}


\end{document}

Making the right angle mark on a right angle triangle?

1 Answers1