# Geometry Drawings: Coloring Arcs

I need to color in arc BC red and make my points D and C darker. Does anyone know how to do this?

\documentclass[10pt]{article}
\usepackage[utf8]{inputenc}
\usepackage{pgf,tikz}
\usetikzlibrary{arrows}
\pagestyle{empty}
\begin{document}
\definecolor{qqttzz}{rgb}{0,0.2,0.6}
\definecolor{ttqqqq}{rgb}{0.2,0,0}
\definecolor{xdxdff}{rgb}{0.49,0.49,1}
\definecolor{qqqqff}{rgb}{0,0,1}
\begin{tikzpicture}[line cap=round,line join=round,>=triangle 45,x=1.0cm,y=1.0cm]
\clip(-4.3,-5.28) rectangle (22.8,6.3);
\draw(2.64,1.26) circle (3.73cm);
\draw [color=ttqqqq] (0.28,-1.63)-- (6.26,2.16);
\draw [color=qqttzz] (2.64,1.26)-- (0.28,-1.63);
\draw (2.16,4.96)-- (0.28,-1.63);
\draw [color=qqttzz] (2.64,1.26)-- (2.16,4.96);
\draw [color=qqttzz] (2.64,1.26)-- (6.26,2.16);
\begin{scriptsize}
\fill [color=qqqqff] (2.64,1.26) circle (1.5pt);
\draw[color=qqqqff] (2.78,1.54) node {$A$};
\fill [color=qqqqff] (2.16,4.96) circle (1.5pt);
\draw[color=qqqqff] (2.32,5.24) node {$B$};
\fill [color=xdxdff] (6.26,2.16) circle (1.5pt);
\draw[color=xdxdff] (6.42,2.44) node {$C$};
\fill [color=xdxdff] (0.28,-1.63) circle (1.5pt);
\draw[color=xdxdff] (0.44,-1.34) node {$D$};
\end{scriptsize}
\end{tikzpicture}

\begin{center}
$\displaystyle\angle BDC = \frac{1}{2} \widehat{BC}$
\end{center}

\end{document}


Also how do I make midpoint hashmarks for segments BA, DA and AC?

I want my drawings to look something like this, but with midpoint hashmarks for the radii:

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– Peter Grill Feb 21 '13 at 6:49

Basic figures like this are better drawn directly in tikz:

## Code:

\documentclass[border=5pt]{standalone}
\usepackage{tikz}
\usetikzlibrary{calc}

\newcommand*{\AAngle}{220}%
\newcommand*{\BAngle}{20}%
\newcommand*{\CAngle}{80}%

\begin{document}
\begin{tikzpicture}[ultra thick, line cap=round,line join=round]
\coordinate (Origin) at (0,0);

\draw [brown]
(Origin)  node [left, black] {$O$}
-- (B) node [right, black] {$B$}
-- (A) node [below left, black] {$A$}
-- (C) node [above, black] {$C$}
-- cycle;

\path (Origin) -- (B) node [midway, sloped] {$\mid$};
\path (Origin) -- (C) node [midway, sloped] {$\mid$};

\end{tikzpicture}
\end{document}

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Thank you both!!! – Lorraine Jane Feb 21 '13 at 8:20

With some basic commands from Tikz you can try : ( but there are a lot of others with Tikz)

\documentclass[10pt]{article}
\usepackage{tikz}

\begin{document}

\begin{tikzpicture}
\draw[red] (0,0) (20:3cm)   arc (20:100:3cm);
\draw[blue] (0,0) (100:3cm) arc (100:380:3cm);
\fill [color=gray] (20:3cm) circle (1.5pt) node[right,text=black]  {$C$}
(100:3cm) circle (1.5pt) node[above,text=black]  {$D$};
\node[red] at (55:3 cm) {//};
\end{tikzpicture}

\end{document}


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