I am following tikz tutorial and my code has reached to this point:

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{decorations.pathmorphing}
\usetikzlibrary{decorations.shapes}
\usetikzlibrary{patterns}
\usetikzlibrary{calc}
\usepackage{verbatim}

\begin{document}

\tikzset{Yasser grid/.style={help lines,color=blue!50}}
\begin{tikzpicture}[scale=5]
\clip (-0.1,-0.2) rectangle (1.1, .75);
\draw [Yasser grid, step=0.5cm] (-1.4,-1.4) grid (1.4,1.4);
\draw (-1.5,0) -- (1.5,0);
\draw (0,1.5) -- (0,-1.5);
\draw (0,0) circle (1cm);
\draw (3mm,0mm) arc (0:30:3mm);

(0,0) -- (3mm,0mm) arc (0:30:3mm) -- cycle;
\draw [red, very thick] (30:1cm) -- +(0, -0.5);
\draw [blue, very thick] (30:1cm) ++(0, -0.5) -- (0,0);
\draw [green, very thick] (0,0) -- (30:1cm);
\draw [orange, very thick] (1,0) -- (30: 1.1547cm);
\path [name path=upward line](1,0) -- (1,1);
\path [name path=sloped line](0,0) -- (30: 1.5cm);
\draw [name intersections={of=upward line and sloped line, by=x}][very thick , orange] (1,0) -- (x);

\end{tikzpicture}
\end{document}


I have seen these posts:

I am using TexShop (MacOS) and I followed the instruction in the first post above. Before updating the tikz and after updating it, I am receiving the same error which is similar to the second post above:

Package pgfkeys Error: I do not know the key '/tikz/name path' and I am going to ignore it. Perhaps you misspelled it.


If I comment out the \path command every thing is fine. Am I still not using the latest version of tikz? But I have downloaded the latest version and installed it accordingly. Is there any manual on how to completely remove the tikz and install it in texmf-local instead?

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This is the exact place I got stuck as well: nowhere, up to this point in the tutorial, do they mention the command usetikzlibrary. –  drozzy Mar 26 '12 at 15:36

You need to load the intersections library:
\usetikzlibrary{intersections}

See 13.3.2 Intersections of Arbitrary Paths in the TikZ 2.10 manual, which explains also name path=... and name intersections=....