# Half annulus 1st and 2nd quadrant

#### dwsmith

##### Well-known member
I am trying to make a annulus oriented counterclockwise so with arrows.

So the annulus goes from delta to R on the positive x axis then circles around to -R and goes to -delta and circles around from -delta to delta.

#### Evgeny.Makarov

##### Well-known member
MHB Math Scholar
Like this?

Code:
 \usetikzlibrary{arrows,decorations.markings}
\begin{tikzpicture}[>=stealth']
\newcommand\delt{1.5}
\newcommand\R{2}
\draw[->] (-3,0) -- (3,0);
\draw[->] (0,-1) -- (0,3);
\node[below] at (\R,0) {$R$};
\node[below] at (\delt,0) {$\delta$};
\draw[
thick,
decoration={
markings,
mark=at position 2cm with {\arrow{>}},
mark=at position 8cm with {\arrow{>}}},
postaction={decorate}]
(\R,0) arc[start angle=0,end angle=180,radius=\R] --
(-\delt,0) arc[start angle=180,end angle=0,radius=\delt] -- cycle;
\end{tikzpicture}

#### dwsmith

##### Well-known member
Like this?

Code:
 \usetikzlibrary{arrows,decorations.markings}
\begin{tikzpicture}[>=stealth']
\newcommand\delt{1.5}
\newcommand\R{2}
\draw[->] (-3,0) -- (3,0);
\draw[->] (0,-1) -- (0,3);
\node[below] at (\R,0) {$R$};
\node[below] at (\delt,0) {$\delta$};
\draw[
thick,
decoration={
markings,
mark=at position 2cm with {\arrow{>}},
mark=at position 8cm with {\arrow{>}}},
postaction={decorate}]
(\R,0) arc[start angle=0,end angle=180,radius=\R] --
(-\delt,0) arc[start angle=180,end angle=0,radius=\delt] -- cycle;
\end{tikzpicture}
What can I change to make the annulus wider?

#### Evgeny.Makarov

##### Well-known member
MHB Math Scholar
There are \newcommand's in the beginning that define delta and R.

#### Krizalid

##### Active member
I find a lot of work of making pictures on LaTeX, I do rather prefer Corel Draw which can give you amazing results and you can export images on EPS.