# Circles and shaded areas with TikZ

I want to draw this with TikZ with the inner of the 'triangle' being shaded (north west lines)

I have no idea how I can do this. Here is what I have so far:

\documentclass{scrartcl}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}
\usepackage{tikz}
\usetikzlibrary{patterns}

\begin{document}
\begin{figure}[h]
\centering
\begin{tikzpicture}[scale=3]
\draw[densely dashed] (-1,0) arc (360:0:1);
\end{tikzpicture}
\end{figure}
\end{document}


This is not really much, sorry :/

If the curves of the triangle can be cosmetic, then you can just use to[bend right=15].

## Code

\documentclass[margin=10pt]{standalone}
\usepackage{tikz}
\usetikzlibrary{patterns}

\begin{document}
\begin{tikzpicture}[scale=3]
\draw (340:1) arc (340:200:1);
\draw[dotted] (200:1) arc (200:180:1);
\draw[dotted] (340:1) arc (340:360:1);
\filldraw[pattern=north west lines,line join=round] (90:1)
to[bend right=15] (.5,0)
-- (-.5,0)
to[bend right=15] cycle
;
\end{tikzpicture}
\end{document}

• Thank you! What parameters do I have to change if I want the cusp above become more sharp? – user112042 Aug 15 '16 at 22:34
• @mathmarseille As in accentuate the curve? You can increase the number in to[bend right=15] to whatever you want. – Alenanno Aug 15 '16 at 22:35
• Thank you! What can I do if I want to draw not the whole circle but only the circle segment 340 to 200°? And is it also possible to end this with ... ? – user112042 Aug 15 '16 at 22:49
• @mathmarseille See edit. What do you mean end it with ... ? – Alenanno Aug 15 '16 at 22:53
• I want to indicate that the circle proceeds, so the ... – user112042 Aug 15 '16 at 22:59