# Draw three half-lines with TikZ

How with TikZ to draw three half-lines from one (center) point, with equal angles between each two of the half-lines?

I attach a rough drawing:

The main question is how to calculate the coordinates of the end-points of the lines.

Use polar coordinates.

Dividing 360 by the number or your segments and using a \foreach, you don't even need to calculate your angles manually.

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{shapes.geometric}
\begin{document}
\begin{tikzpicture}
\node[draw, fill=cyan, ellipse, text width=4pt] (a) {};
\draw (a) -- +(0:4cm);
\draw (a) -- +(120:4cm);
\draw (a) -- +(240:4cm);
\end{tikzpicture}

You could also use a foreach: dividing 360 by the number or segments,
you don't even need to calculate your angles manually.

\begin{tikzpicture}
\node[draw, fill=cyan, ellipse, text width=4pt] (a) {};
\pgfmathsetmacro{\myangle}{360/3}
\foreach \i in {0,1,2}
\draw (a) -- +(\i*\myangle:4cm);
\end{tikzpicture}
\end{document}