diff --git a/documents/GeoTopo/Arbeitszeit.md b/documents/GeoTopo/Arbeitszeit.md
index e3583cf..b5f2aa2 100644
--- a/documents/GeoTopo/Arbeitszeit.md
+++ b/documents/GeoTopo/Arbeitszeit.md
@@ -40,4 +40,5 @@ in dem Erstellen dieses Skripts steckt:
 |21.01.2014 | 19:30 - 21:30 | Digitalisieren der Vorlesung von 21.01.2014
 |22.01.2014 | 06:00 - 06:30 | TikZ'en eines Bildes
 |22.01.2014 | 07:15 - 07:35 | TikZ'en eines Bildes
-|22.01.2014 | 00:00 - 10:00 | TikZ'en eines Bildes und Bemerkungen
+|23.01.2014 | 09:00 - 10:00 | TikZ'en eines Bildes und Bemerkungen
+|23.01.2014 | 10:30 - 12:15 | TikZ'en von Bildern
diff --git a/documents/GeoTopo/GeoTopo.pdf b/documents/GeoTopo/GeoTopo.pdf
index a2d9ee1..f84eb38 100644
Binary files a/documents/GeoTopo/GeoTopo.pdf and b/documents/GeoTopo/GeoTopo.pdf differ
diff --git a/documents/GeoTopo/Kapitel4.tex b/documents/GeoTopo/Kapitel4.tex
index 9baf0f6..58716c8 100644
--- a/documents/GeoTopo/Kapitel4.tex
+++ b/documents/GeoTopo/Kapitel4.tex
@@ -664,11 +664,11 @@ $\overset{\text{Strahlensatz}}{\Rightarrow} \frac{a}{h_c} = \frac{c}{h_a} \right
 \begin{figure}[ht]
     \centering
     \subfloat[$a,b$ sind Katheten und $c$ ist die Hypothenuse]{
-        \input{figures/todo.tex}
+        \input{figures/pythagoras.tex}
         \label{fig:pythagoras-bezeichnungen}
     }%
     \subfloat[Beweisskizze]{
-        \input{figures/todo.tex}
+        \input{figures/pythagoras-2.tex}
         \label{fig:bild-5}
     }%
     \label{fig:flaechengleichheit}
@@ -699,12 +699,12 @@ $\overset{\text{Strahlensatz}}{\Rightarrow} \frac{a}{h_c} = \frac{c}{h_a} \right
 
             \begin{figure}[ht]
                 \centering
-                \subfloat[Schritt 1 (Bild 10)]{
-                    \input{figures/todo.tex}
+                \subfloat[Schritt 1]{
+                    \input{figures/coordinate-system-1.tex}
                     \label{fig:14.13.1}
                 }%
-                \subfloat[Schritt 2 (Bild 11)]{
-                    \input{figures/todo.tex}
+                \subfloat[Schritt 2]{
+                    \input{figures/coordinate-system-2.tex}
                     \label{fig:14.13.2}
                 }%
                 \label{fig:14.13.0.1}
@@ -729,8 +729,8 @@ $\overset{\text{Strahlensatz}}{\Rightarrow} \frac{a}{h_c} = \frac{c}{h_a} \right
             \begin{beweis}[von 2]
                 \begin{figure}[ht]
                     \centering
-                    \subfloat[Schritt 1 (Bild 12)]{
-                        \input{figures/todo.tex}
+                    \subfloat[Schritt 1]{
+                        \input{figures/coordinate-system-2.tex}
                         \label{fig:14.13.3}
                     }%
                     \subfloat[Schritt 2 (Bild 13)]{
diff --git a/documents/GeoTopo/figures/coordinate-system-1.tex b/documents/GeoTopo/figures/coordinate-system-1.tex
new file mode 100644
index 0000000..8ca868f
--- /dev/null
+++ b/documents/GeoTopo/figures/coordinate-system-1.tex
@@ -0,0 +1,13 @@
+\begin{tikzpicture}
+    \tkzSetUpPoint[shape=circle,size=10,color=black,fill=black]
+    \tkzSetUpLine[line width=1]
+    \tkzDefPoints{0/0/O, 1/0/X, 0/1/Y, 2/1/P}
+    \tkzDrawLine[add=3 and 2](O,X)
+    \tkzLabelLine[below,pos=3](O,X){$g_1$}
+    \tkzLabelLine[right,pos=3](O,Y){$g_2$}
+    \tkzDrawLine[add=3 and 2](O,Y)
+
+    \tkzLabelPoint(P){$P$}
+    \node at ($(-2,2)$){$X$};
+    \tkzDrawPoints(P)
+\end{tikzpicture}
diff --git a/documents/GeoTopo/figures/coordinate-system-2.tex b/documents/GeoTopo/figures/coordinate-system-2.tex
new file mode 100644
index 0000000..4e5212c
--- /dev/null
+++ b/documents/GeoTopo/figures/coordinate-system-2.tex
@@ -0,0 +1,28 @@
+\begin{tikzpicture}
+    \tkzSetUpPoint[shape=circle,size=10,color=black,fill=black]
+    \tkzSetUpLine[line width=1]
+    \tkzDefPoints{0/0/O, 1/0/X, 0/1/Y, 2/1/P}
+    \tkzDrawLine[add=3 and 2](O,X)
+    \tkzLabelLine[below,pos=3](O,X){$g_1$}
+    \tkzLabelLine[right,pos=3](O,Y){$g_2$}
+    \tkzDrawLine[add=3 and 2](O,Y)
+
+    \tkzDefLine[orthogonal=through P,/tikz/overlay](O,X) \tkzGetPoint{helper}
+    \tkzInterLL(O,X)(P,helper) \tkzGetPoint{xp}
+    \draw [decorate,decoration={brace,amplitude=4pt,mirror}]
+        (O) -- (xp) node [black,midway,xshift=0cm, yshift=-0.3cm] 
+        {\footnotesize $x_P$};
+
+    \tkzDefLine[orthogonal=through P,/tikz/overlay](O,Y) \tkzGetPoint{helper}
+    \tkzInterLL(O,Y)(P,helper) \tkzGetPoint{yp}
+    \draw [decorate,decoration={brace,amplitude=4pt}]
+        (O) -- (yp) node [black,midway,xshift=-0.4cm] 
+        {\footnotesize $y_P$};
+
+    \tkzDrawPolygon(O,xp,P,yp)
+
+    \tkzLabelPoint[above right](P){$P$}
+    \tkzLabelPoint[below left](O){$0$}
+    \node at ($(-2,2)$){$X$};
+    \tkzDrawPoints(P)
+\end{tikzpicture}
diff --git a/documents/GeoTopo/figures/coordinate-system-3.tex b/documents/GeoTopo/figures/coordinate-system-3.tex
new file mode 100644
index 0000000..f39b870
--- /dev/null
+++ b/documents/GeoTopo/figures/coordinate-system-3.tex
@@ -0,0 +1,43 @@
+\begin{tikzpicture}
+    \tkzSetUpPoint[shape=circle,size=10,color=black,fill=black]
+    \tkzSetUpLine[line width=1]
+    \tkzDefPoints{0/0/O, 1/0/X, 0/1/Y, 2/1/P, 3/3/Q}
+    \tkzDrawLine[add=3 and 2.2](O,X)
+    \tkzLabelLine[below,pos=3](O,X){$g_1$}
+    \tkzLabelLine[left,pos=3](O,Y){$g_2$}
+    \tkzDrawLine[add=3 and 2.2](O,Y)
+
+    \tkzDefLine[orthogonal=through P,/tikz/overlay](O,X) \tkzGetPoint{helper}
+    \tkzInterLL(O,X)(P,helper) \tkzGetPoint{xp}
+    \draw [decorate,decoration={brace,amplitude=4pt,mirror}]
+        (O) -- (xp) node [black,midway,xshift=0cm, yshift=-0.3cm] 
+        {\footnotesize $x_P$};
+
+    \tkzDefLine[orthogonal=through P,/tikz/overlay](O,Y) \tkzGetPoint{helper}
+    \tkzInterLL(O,Y)(P,helper) \tkzGetPoint{yp}
+    \draw [decorate,decoration={brace,amplitude=4pt}]
+        (O) -- (yp) node [black,midway,xshift=-0.4cm] 
+        {\footnotesize $y_P$};
+
+    \tkzDrawPolygon(O,xp,P,yp)
+
+    \tkzDefLine[orthogonal=through Q,/tikz/overlay](O,X) \tkzGetPoint{helper}
+    \tkzInterLL(O,X)(Q,helper) \tkzGetPoint{xq}
+    \tkzDefLine[orthogonal=through Q,/tikz/overlay](O,Y) \tkzGetPoint{helper}
+    \tkzInterLL(O,Y)(Q,helper) \tkzGetPoint{yq}
+
+    \tkzInterLL(yp,P)(Q,xq) \tkzGetPoint{qxp}
+    \tkzInterLL(xp,P)(Q,yq) \tkzGetPoint{R}
+
+    \tkzDrawPolygon(O,xq,Q,yq)
+
+    \tkzDrawSegments[green](xp,xq R,Q)
+    \tkzDrawSegments[very thick,orange](yp,yq P,R)
+
+    \tkzLabelPoint[above right](P){$P$}
+    \tkzLabelPoint[above right](Q){$Q$}
+    \tkzLabelPoint[below left](O){$0$}
+    \tkzLabelPoint[above](R){$R$}
+    \node at ($(-2,2)$){$X$};
+    \tkzDrawPoints(P,Q,R)
+\end{tikzpicture}
diff --git a/documents/GeoTopo/figures/pythagoras-2.tex b/documents/GeoTopo/figures/pythagoras-2.tex
new file mode 100644
index 0000000..ca889ed
--- /dev/null
+++ b/documents/GeoTopo/figures/pythagoras-2.tex
@@ -0,0 +1,25 @@
+\begin{tikzpicture}
+    \tkzSetUpPoint[shape=circle,size=10,color=black,fill=black]
+    \tkzSetUpLine[line width=1]
+    \tkzDefPoints{0/0/A, 4/0/B, 4/4/C, 0/4/D, 1/0/W, 4/1/X, 3/4/Y, 0/3/Z}
+    \tkzDrawPolygon(A,B,C,D)
+    \tkzDrawPolygon(W,X,Y,Z)
+    \tkzLabelSegment[below](A,W){$b$}
+    \tkzLabelSegment[below](W,B){$a$}
+    \tkzLabelSegment[right](B,X){$b$}
+    \tkzLabelSegment[right](X,C){$a$}
+    \tkzLabelSegment[above](C,Y){$b$}
+    \tkzLabelSegment[above](Y,D){$a$}
+    \tkzLabelSegment[left](D,Z){$b$}
+    \tkzLabelSegment[left](Z,A){$a$}
+    \tkzLabelAngle[pos=-0.24](D,C,B){$\cdot$}
+    \tkzMarkAngle[arc=l,size=0.4cm](D,C,B)
+    \tkzLabelAngle[pos=0.24](C,B,A){$\cdot$}
+    \tkzMarkAngle[arc=l,size=0.4cm](C,B,A)
+    \tkzLabelAngle[pos=0.24](B,A,D){$\cdot$}
+    \tkzMarkAngle[arc=l,size=0.4cm](B,A,D)
+    \tkzLabelAngle[pos=0.24](A,D,C){$\cdot$}
+    \tkzMarkAngle[arc=l,size=0.4cm](A,D,C)
+    \tkzLabelAngle[pos=0.24](W,Z,Y){$\gamma$}
+    \tkzMarkAngle[arc=l,size=0.4cm](W,Z,Y)
+\end{tikzpicture}
diff --git a/documents/GeoTopo/figures/pythagoras.tex b/documents/GeoTopo/figures/pythagoras.tex
new file mode 100644
index 0000000..6a02a24
--- /dev/null
+++ b/documents/GeoTopo/figures/pythagoras.tex
@@ -0,0 +1,16 @@
+\begin{tikzpicture}
+    \tkzSetUpPoint[shape=circle,size=10,color=black,fill=black]
+    \tkzSetUpLine[line width=1]
+    \tkzDefPoints{0/0/A, 5/0/B}
+    \tkzInterCC[R,/tikz/overlay](A,4cm)(B,3cm) \tkzGetPoints{C}{D}
+    \tkzDrawPolygon(A,B,C)
+    \tkzDrawPoints(A,B,C)
+    \tkzLabelSegment[below](A,B){$c$}
+    \tkzLabelSegment[above left](A,C){$b$}
+    \tkzLabelSegment[above right](B,C){$a$}
+    \tkzLabelPoint[below](A){$A$}
+    \tkzLabelPoint[below](B){$B$}
+    \tkzLabelPoint[above](C){$C$}
+    \tkzLabelAngle[pos=0.24](A,C,B){$\cdot$}
+    \tkzMarkAngle[arc=l,size=0.4cm](A,C,B)
+\end{tikzpicture}
diff --git a/tikz/coordinate-system-1/Makefile b/tikz/coordinate-system-1/Makefile
new file mode 100644
index 0000000..56b9446
--- /dev/null
+++ b/tikz/coordinate-system-1/Makefile
@@ -0,0 +1,31 @@
+SOURCE  = coordinate-system-1
+DELAY   = 80
+DENSITY = 300
+WIDTH   = 512
+
+make:
+	pdflatex $(SOURCE).tex -output-format=pdf
+	make clean
+
+clean:
+	rm -rf  $(TARGET) *.class *.html *.log *.aux *.data *.gnuplot
+
+gif:
+	pdfcrop $(SOURCE).pdf
+	convert -verbose -delay $(DELAY) -loop 0 -density $(DENSITY) $(SOURCE)-crop.pdf $(SOURCE).gif
+	make clean
+
+png:
+	make
+	make svg
+	inkscape $(SOURCE).svg -w $(WIDTH) --export-png=$(SOURCE).png
+
+transparentGif:
+	convert $(SOURCE).pdf -transparent white result.gif
+	make clean
+
+svg:
+	#inkscape $(SOURCE).pdf --export-plain-svg=$(SOURCE).svg
+	pdf2svg $(SOURCE).pdf $(SOURCE).svg
+	# Necessary, as pdf2svg does not always create valid svgs:
+	inkscape $(SOURCE).svg --export-plain-svg=$(SOURCE).svg
diff --git a/tikz/coordinate-system-1/Readme.md b/tikz/coordinate-system-1/Readme.md
new file mode 100644
index 0000000..ddccb6f
--- /dev/null
+++ b/tikz/coordinate-system-1/Readme.md
@@ -0,0 +1,3 @@
+Compiled example
+----------------
+![Example](coordinate-system-1.png)
diff --git a/tikz/coordinate-system-1/coordinate-system-1.png b/tikz/coordinate-system-1/coordinate-system-1.png
new file mode 100644
index 0000000..53632fb
Binary files /dev/null and b/tikz/coordinate-system-1/coordinate-system-1.png differ
diff --git a/tikz/coordinate-system-1/coordinate-system-1.tex b/tikz/coordinate-system-1/coordinate-system-1.tex
new file mode 100644
index 0000000..2da01d7
--- /dev/null
+++ b/tikz/coordinate-system-1/coordinate-system-1.tex
@@ -0,0 +1,21 @@
+\documentclass[varwidth=true, border=2pt]{standalone}
+\usepackage{tkz-euclide}
+\usepackage{tikz}
+\usetikzlibrary{patterns}
+
+\begin{document}
+\usetkzobj{all}
+\begin{tikzpicture}
+    \tkzSetUpPoint[shape=circle,size=10,color=black,fill=black]
+    \tkzSetUpLine[line width=1]
+    \tkzDefPoints{0/0/O, 1/0/X, 0/1/Y, 2/1/P}
+    \tkzDrawLine[add=3 and 2](O,X)
+    \tkzLabelLine[below,pos=3](O,X){$g_1$}
+    \tkzLabelLine[right,pos=3](O,Y){$g_2$}
+    \tkzDrawLine[add=3 and 2](O,Y)
+
+    \tkzLabelPoint(P){$P$}
+    \node at ($(-2,2)$){$X$};
+    \tkzDrawPoints(P)
+\end{tikzpicture}
+\end{document}
diff --git a/tikz/coordinate-system-2/Makefile b/tikz/coordinate-system-2/Makefile
new file mode 100644
index 0000000..0e96a26
--- /dev/null
+++ b/tikz/coordinate-system-2/Makefile
@@ -0,0 +1,31 @@
+SOURCE  = coordinate-system-2
+DELAY   = 80
+DENSITY = 300
+WIDTH   = 512
+
+make:
+	pdflatex $(SOURCE).tex -output-format=pdf
+	make clean
+
+clean:
+	rm -rf  $(TARGET) *.class *.html *.log *.aux *.data *.gnuplot
+
+gif:
+	pdfcrop $(SOURCE).pdf
+	convert -verbose -delay $(DELAY) -loop 0 -density $(DENSITY) $(SOURCE)-crop.pdf $(SOURCE).gif
+	make clean
+
+png:
+	make
+	make svg
+	inkscape $(SOURCE).svg -w $(WIDTH) --export-png=$(SOURCE).png
+
+transparentGif:
+	convert $(SOURCE).pdf -transparent white result.gif
+	make clean
+
+svg:
+	#inkscape $(SOURCE).pdf --export-plain-svg=$(SOURCE).svg
+	pdf2svg $(SOURCE).pdf $(SOURCE).svg
+	# Necessary, as pdf2svg does not always create valid svgs:
+	inkscape $(SOURCE).svg --export-plain-svg=$(SOURCE).svg
diff --git a/tikz/coordinate-system-2/Readme.md b/tikz/coordinate-system-2/Readme.md
new file mode 100644
index 0000000..36d343f
--- /dev/null
+++ b/tikz/coordinate-system-2/Readme.md
@@ -0,0 +1,3 @@
+Compiled example
+----------------
+![Example](coordinate-system-2.png)
diff --git a/tikz/coordinate-system-2/coordinate-system-2.png b/tikz/coordinate-system-2/coordinate-system-2.png
new file mode 100644
index 0000000..8690ca8
Binary files /dev/null and b/tikz/coordinate-system-2/coordinate-system-2.png differ
diff --git a/tikz/coordinate-system-2/coordinate-system-2.tex b/tikz/coordinate-system-2/coordinate-system-2.tex
new file mode 100644
index 0000000..8c66aba
--- /dev/null
+++ b/tikz/coordinate-system-2/coordinate-system-2.tex
@@ -0,0 +1,37 @@
+\documentclass[varwidth=true, border=2pt]{standalone}
+\usepackage{tkz-euclide}
+\usepackage{tikz}
+\usetikzlibrary{decorations.pathreplacing}
+
+
+\begin{document}
+\usetkzobj{all}
+\begin{tikzpicture}
+    \tkzSetUpPoint[shape=circle,size=10,color=black,fill=black]
+    \tkzSetUpLine[line width=1]
+    \tkzDefPoints{0/0/O, 1/0/X, 0/1/Y, 2/1/P}
+    \tkzDrawLine[add=3 and 2](O,X)
+    \tkzLabelLine[below,pos=3](O,X){$g_1$}
+    \tkzLabelLine[right,pos=3](O,Y){$g_2$}
+    \tkzDrawLine[add=3 and 2](O,Y)
+
+    \tkzDefLine[orthogonal=through P,/tikz/overlay](O,X) \tkzGetPoint{helper}
+    \tkzInterLL(O,X)(P,helper) \tkzGetPoint{xp}
+    \draw [decorate,decoration={brace,amplitude=4pt,mirror}]
+        (O) -- (xp) node [black,midway,xshift=0cm, yshift=-0.3cm] 
+        {\footnotesize $x_P$};
+
+    \tkzDefLine[orthogonal=through P,/tikz/overlay](O,Y) \tkzGetPoint{helper}
+    \tkzInterLL(O,Y)(P,helper) \tkzGetPoint{yp}
+    \draw [decorate,decoration={brace,amplitude=4pt}]
+        (O) -- (yp) node [black,midway,xshift=-0.4cm] 
+        {\footnotesize $y_P$};
+
+    \tkzDrawPolygon(O,xp,P,yp)
+
+    \tkzLabelPoint[above right](P){$P$}
+    \tkzLabelPoint[below left](O){$0$}
+    \node at ($(-2,2)$){$X$};
+    \tkzDrawPoints(P)
+\end{tikzpicture}
+\end{document}
diff --git a/tikz/coordinate-system-3/Makefile b/tikz/coordinate-system-3/Makefile
new file mode 100644
index 0000000..cb9854b
--- /dev/null
+++ b/tikz/coordinate-system-3/Makefile
@@ -0,0 +1,31 @@
+SOURCE  = coordinate-system-3
+DELAY   = 80
+DENSITY = 300
+WIDTH   = 512
+
+make:
+	pdflatex $(SOURCE).tex -output-format=pdf
+	make clean
+
+clean:
+	rm -rf  $(TARGET) *.class *.html *.log *.aux *.data *.gnuplot
+
+gif:
+	pdfcrop $(SOURCE).pdf
+	convert -verbose -delay $(DELAY) -loop 0 -density $(DENSITY) $(SOURCE)-crop.pdf $(SOURCE).gif
+	make clean
+
+png:
+	make
+	make svg
+	inkscape $(SOURCE).svg -w $(WIDTH) --export-png=$(SOURCE).png
+
+transparentGif:
+	convert $(SOURCE).pdf -transparent white result.gif
+	make clean
+
+svg:
+	#inkscape $(SOURCE).pdf --export-plain-svg=$(SOURCE).svg
+	pdf2svg $(SOURCE).pdf $(SOURCE).svg
+	# Necessary, as pdf2svg does not always create valid svgs:
+	inkscape $(SOURCE).svg --export-plain-svg=$(SOURCE).svg
diff --git a/tikz/coordinate-system-3/Readme.md b/tikz/coordinate-system-3/Readme.md
new file mode 100644
index 0000000..8c755e6
--- /dev/null
+++ b/tikz/coordinate-system-3/Readme.md
@@ -0,0 +1,3 @@
+Compiled example
+----------------
+![Example](coordinate-system-3.png)
diff --git a/tikz/coordinate-system-3/coordinate-system-3.png b/tikz/coordinate-system-3/coordinate-system-3.png
new file mode 100644
index 0000000..5124580
Binary files /dev/null and b/tikz/coordinate-system-3/coordinate-system-3.png differ
diff --git a/tikz/coordinate-system-3/coordinate-system-3.tex b/tikz/coordinate-system-3/coordinate-system-3.tex
new file mode 100644
index 0000000..0abee62
--- /dev/null
+++ b/tikz/coordinate-system-3/coordinate-system-3.tex
@@ -0,0 +1,52 @@
+\documentclass[varwidth=true, border=2pt]{standalone}
+\usepackage{tkz-euclide}
+\usepackage{tikz}
+\usetikzlibrary{decorations.pathreplacing}
+
+
+\begin{document}
+\usetkzobj{all}
+\begin{tikzpicture}
+    \tkzSetUpPoint[shape=circle,size=10,color=black,fill=black]
+    \tkzSetUpLine[line width=1]
+    \tkzDefPoints{0/0/O, 1/0/X, 0/1/Y, 2/1/P, 3/3/Q}
+    \tkzDrawLine[add=3 and 2.2](O,X)
+    \tkzLabelLine[below,pos=3](O,X){$g_1$}
+    \tkzLabelLine[left,pos=3](O,Y){$g_2$}
+    \tkzDrawLine[add=3 and 2.2](O,Y)
+
+    \tkzDefLine[orthogonal=through P,/tikz/overlay](O,X) \tkzGetPoint{helper}
+    \tkzInterLL(O,X)(P,helper) \tkzGetPoint{xp}
+    \draw [decorate,decoration={brace,amplitude=4pt,mirror}]
+        (O) -- (xp) node [black,midway,xshift=0cm, yshift=-0.3cm] 
+        {\footnotesize $x_P$};
+
+    \tkzDefLine[orthogonal=through P,/tikz/overlay](O,Y) \tkzGetPoint{helper}
+    \tkzInterLL(O,Y)(P,helper) \tkzGetPoint{yp}
+    \draw [decorate,decoration={brace,amplitude=4pt}]
+        (O) -- (yp) node [black,midway,xshift=-0.4cm] 
+        {\footnotesize $y_P$};
+
+    \tkzDrawPolygon(O,xp,P,yp)
+
+    \tkzDefLine[orthogonal=through Q,/tikz/overlay](O,X) \tkzGetPoint{helper}
+    \tkzInterLL(O,X)(Q,helper) \tkzGetPoint{xq}
+    \tkzDefLine[orthogonal=through Q,/tikz/overlay](O,Y) \tkzGetPoint{helper}
+    \tkzInterLL(O,Y)(Q,helper) \tkzGetPoint{yq}
+
+    \tkzInterLL(yp,P)(Q,xq) \tkzGetPoint{qxp}
+    \tkzInterLL(xp,P)(Q,yq) \tkzGetPoint{R}
+
+    \tkzDrawPolygon(O,xq,Q,yq)
+
+    \tkzDrawSegments[green](xp,xq R,Q)
+    \tkzDrawSegments[very thick,orange](yp,yq P,R)
+
+    \tkzLabelPoint[above right](P){$P$}
+    \tkzLabelPoint[above right](Q){$Q$}
+    \tkzLabelPoint[below left](O){$0$}
+    \tkzLabelPoint[above](R){$R$}
+    \node at ($(-2,2)$){$X$};
+    \tkzDrawPoints(P,Q,R)
+\end{tikzpicture}
+\end{document}
diff --git a/tikz/pythagoras-2/Makefile b/tikz/pythagoras-2/Makefile
new file mode 100644
index 0000000..18c514d
--- /dev/null
+++ b/tikz/pythagoras-2/Makefile
@@ -0,0 +1,31 @@
+SOURCE  = pythagoras-2
+DELAY   = 80
+DENSITY = 300
+WIDTH   = 512
+
+make:
+	pdflatex $(SOURCE).tex -output-format=pdf
+	make clean
+
+clean:
+	rm -rf  $(TARGET) *.class *.html *.log *.aux *.data *.gnuplot
+
+gif:
+	pdfcrop $(SOURCE).pdf
+	convert -verbose -delay $(DELAY) -loop 0 -density $(DENSITY) $(SOURCE)-crop.pdf $(SOURCE).gif
+	make clean
+
+png:
+	make
+	make svg
+	inkscape $(SOURCE).svg -w $(WIDTH) --export-png=$(SOURCE).png
+
+transparentGif:
+	convert $(SOURCE).pdf -transparent white result.gif
+	make clean
+
+svg:
+	#inkscape $(SOURCE).pdf --export-plain-svg=$(SOURCE).svg
+	pdf2svg $(SOURCE).pdf $(SOURCE).svg
+	# Necessary, as pdf2svg does not always create valid svgs:
+	inkscape $(SOURCE).svg --export-plain-svg=$(SOURCE).svg
diff --git a/tikz/pythagoras-2/Readme.md b/tikz/pythagoras-2/Readme.md
new file mode 100644
index 0000000..ca4d7b9
--- /dev/null
+++ b/tikz/pythagoras-2/Readme.md
@@ -0,0 +1,3 @@
+Compiled example
+----------------
+![Example](pythagoras-2.png)
diff --git a/tikz/pythagoras-2/pythagoras-2.png b/tikz/pythagoras-2/pythagoras-2.png
new file mode 100644
index 0000000..815cf33
Binary files /dev/null and b/tikz/pythagoras-2/pythagoras-2.png differ
diff --git a/tikz/pythagoras-2/pythagoras-2.tex b/tikz/pythagoras-2/pythagoras-2.tex
new file mode 100644
index 0000000..3dabb10
--- /dev/null
+++ b/tikz/pythagoras-2/pythagoras-2.tex
@@ -0,0 +1,31 @@
+\documentclass[varwidth=true, border=2pt]{standalone}
+\usepackage{tkz-euclide}
+
+\begin{document}
+\usetkzobj{all}
+\begin{tikzpicture}
+    \tkzSetUpPoint[shape=circle,size=10,color=black,fill=black]
+    \tkzSetUpLine[line width=1]
+    \tkzDefPoints{0/0/A, 4/0/B, 4/4/C, 0/4/D, 1/0/W, 4/1/X, 3/4/Y, 0/3/Z}
+    \tkzDrawPolygon(A,B,C,D)
+    \tkzDrawPolygon(W,X,Y,Z)
+    \tkzLabelSegment[below](A,W){$b$}
+    \tkzLabelSegment[below](W,B){$a$}
+    \tkzLabelSegment[right](B,X){$b$}
+    \tkzLabelSegment[right](X,C){$a$}
+    \tkzLabelSegment[above](C,Y){$b$}
+    \tkzLabelSegment[above](Y,D){$a$}
+    \tkzLabelSegment[left](D,Z){$b$}
+    \tkzLabelSegment[left](Z,A){$a$}
+    \tkzLabelAngle[pos=-0.24](D,C,B){$\cdot$}
+    \tkzMarkAngle[arc=l,size=0.4cm](D,C,B)
+    \tkzLabelAngle[pos=0.24](C,B,A){$\cdot$}
+    \tkzMarkAngle[arc=l,size=0.4cm](C,B,A)
+    \tkzLabelAngle[pos=0.24](B,A,D){$\cdot$}
+    \tkzMarkAngle[arc=l,size=0.4cm](B,A,D)
+    \tkzLabelAngle[pos=0.24](A,D,C){$\cdot$}
+    \tkzMarkAngle[arc=l,size=0.4cm](A,D,C)
+    \tkzLabelAngle[pos=0.24](W,Z,Y){$\gamma$}
+    \tkzMarkAngle[arc=l,size=0.4cm](W,Z,Y)
+\end{tikzpicture}
+\end{document}
diff --git a/tikz/pythagoras/Makefile b/tikz/pythagoras/Makefile
new file mode 100644
index 0000000..6175aa8
--- /dev/null
+++ b/tikz/pythagoras/Makefile
@@ -0,0 +1,31 @@
+SOURCE  = pythagoras
+DELAY   = 80
+DENSITY = 300
+WIDTH   = 512
+
+make:
+	pdflatex $(SOURCE).tex -output-format=pdf
+	make clean
+
+clean:
+	rm -rf  $(TARGET) *.class *.html *.log *.aux *.data *.gnuplot
+
+gif:
+	pdfcrop $(SOURCE).pdf
+	convert -verbose -delay $(DELAY) -loop 0 -density $(DENSITY) $(SOURCE)-crop.pdf $(SOURCE).gif
+	make clean
+
+png:
+	make
+	make svg
+	inkscape $(SOURCE).svg -w $(WIDTH) --export-png=$(SOURCE).png
+
+transparentGif:
+	convert $(SOURCE).pdf -transparent white result.gif
+	make clean
+
+svg:
+	#inkscape $(SOURCE).pdf --export-plain-svg=$(SOURCE).svg
+	pdf2svg $(SOURCE).pdf $(SOURCE).svg
+	# Necessary, as pdf2svg does not always create valid svgs:
+	inkscape $(SOURCE).svg --export-plain-svg=$(SOURCE).svg
diff --git a/tikz/pythagoras/Readme.md b/tikz/pythagoras/Readme.md
new file mode 100644
index 0000000..e5756ab
--- /dev/null
+++ b/tikz/pythagoras/Readme.md
@@ -0,0 +1,3 @@
+Compiled example
+----------------
+![Example](pythagoras.png)
diff --git a/tikz/pythagoras/pythagoras.png b/tikz/pythagoras/pythagoras.png
new file mode 100644
index 0000000..406db24
Binary files /dev/null and b/tikz/pythagoras/pythagoras.png differ
diff --git a/tikz/pythagoras/pythagoras.tex b/tikz/pythagoras/pythagoras.tex
new file mode 100644
index 0000000..3ede1ac
--- /dev/null
+++ b/tikz/pythagoras/pythagoras.tex
@@ -0,0 +1,22 @@
+\documentclass[varwidth=true, border=2pt]{standalone}
+\usepackage{tkz-euclide}
+
+\begin{document}
+\usetkzobj{all}
+\begin{tikzpicture}
+    \tkzSetUpPoint[shape=circle,size=10,color=black,fill=black]
+    \tkzSetUpLine[line width=1]
+    \tkzDefPoints{0/0/A, 5/0/B}
+    \tkzInterCC[R,/tikz/overlay](A,4cm)(B,3cm) \tkzGetPoints{C}{D}
+    \tkzDrawPolygon(A,B,C)
+    \tkzDrawPoints(A,B,C)
+    \tkzLabelSegment[below](A,B){$c$}
+    \tkzLabelSegment[above left](A,C){$b$}
+    \tkzLabelSegment[above right](B,C){$a$}
+    \tkzLabelPoint[below](A){$A$}
+    \tkzLabelPoint[below](B){$B$}
+    \tkzLabelPoint[above](C){$C$}
+    \tkzLabelAngle[pos=0.24](A,C,B){$\cdot$}
+    \tkzMarkAngle[arc=l,size=0.4cm](A,C,B)
+\end{tikzpicture}
+\end{document}