# tikz - stealth arrow makes a drift in a curved line

A stealth arrow makes a drift in a curved line :

\documentclass[tikz]{standalone}
\usetikzlibrary{calc}
\begin{document}

\begin{tikzpicture}

\draw[thick,-stealth]
($(0,0)+(0:1.45)$) arc
[start angle=0,
end angle=72,

\draw[thick,red]
($(0,0)+(0:1.45)$) arc
[start angle=0,
end angle=72,

\end{tikzpicture}

\end{document}


This is not specific to this arrow head. All arrow heads do. This is because you force a piece of a curved path to be straight, and this deforms the path.

You can use bending to cure this. It will rotate the arrow in such a way that the path does not get distorted.

\documentclass[tikz]{standalone}
\usetikzlibrary{calc,bending}
\begin{document}

\begin{tikzpicture}

\draw[thick,-stealth]
($(0,0)+(0:1.45)$) arc
[start angle=0,
end angle=72,

\draw[thick,red]
($(0,0)+(0:1.45)$) arc
[start angle=0,
end angle=72,

\end{tikzpicture}

\end{document}


Notice that for this you do not have to explicitly bend the arrow.

If you bend it, then the arrow will follow the curve (to a very good approximation).

\documentclass[tikz]{standalone}
\usetikzlibrary{calc,arrows.meta,bending}
\begin{document}

\begin{tikzpicture}

\draw[thick,-{Stealth[bend]}]
($(0,0)+(0:1.45)$) arc
[start angle=0,
end angle=72,
($(0,0)+(0:1.45)$) arc