[Tex/LaTex] Tikz: change of origin, polar coordinates

tikz-pgf

enter image description here

I can draw this picture in tikz with codes like
\draw (a,b) node {} -- (c,d);
but for that I have to calculate values of coordinates so that the picture looks good. What I want to do is use this type of code
\draw (0:0) node {} -- (45:1.2) node {} -- (45:2.4) node {} -- (90:3);
which gives me this picture
enter image description here
Is it possible to code in this way such that (90:3) is plotted by considering (45:2.4) as origin not by considering (0:0) as origin?

Best Answer

From TikZ manual (chapter 13.4, page 140, recent version 3.0.1a):

You can prefix coordinates by ++ to make them “relative.” A coordinate such as ++(1cm,0pt) means “1cm to the right of the previous position, making this the new current position.” Relative coordinates are often useful in “local” contexts:

\documentclass[tikz, border=3mm]{standalone}
\begin{document}
\begin{tikzpicture}[every node/.style={circle,fill=black}]
\draw (0:0)    node (a) [pin=330:a] {} -- ++ (45:1.2) node (b) [pin=330:b] {} -- ++
      (45:2.4) node (c) [pin=330:c] {} -- ++ (90:3)   node (d) [pin=330:a] {};
\draw   (b) -- ++ (-15:2) node (e) [pin=330:e] {};
\end{tikzpicture}

gives:

enter image description here

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