tkz-euclide changing labels and size (triangle, inscribed circle)

Question

A friend of me Torbjørn, showed me how to build the image below using tikz

with the following code.

 \documentclass{article}
 \usepackage{tkz-euclide}
 \usetkzobj{all}
 \begin{document}\begin{minipage}{0.5\textwidth}
 I en $\Delta ABC$ er $\angle A = 90^{\circ}$ En sirkel med sentrum i 
 $S$ er innskrevet i trekanten. Sidene $AC$ og $BC$ tangerer sirkelen
 i punktene $D$ og $E$. Linjen gjennom $B$ og $S$ skjærer $DE$ i $F$. \\
 \\
 Se skissen til høyre. \\
 \\
 Du får oppgitt at $DC=EC$.\\
 \\
 Vi setter $\angle ABC = v, \: \angle BCU = u, \: $ og $\angle BFE=x$\\
 \end{minipage}
 \begin{minipage}{0.5\textwidth}
 \begin{tikzpicture}[scale=1.5]
   \tkzInit[ymin=-1,ymax=5,xmin=-1,xmax=5]
   \tkzClip 
   \tkzDefPoint(0,0){A}
   \tkzDefPoint(4,0){B}
   \tkzDefPoint(0,4){C}
   \tkzDefCircle[in](A,B,C)
     \tkzGetPoint{S}
     \tkzGetLength{rSN}
   \tkzDrawPoints(A,B,C)
   \tkzDrawCircle[R](S,\rSN pt)
   \tkzDrawPolygon[very thick](A,B,C)
   \tkzInterLC[R](A,C)(S,\rSN pt) \tkzGetFirstPoint{D}
   \tkzInterLC[R](B,C)(S,\rSN pt) \tkzGetFirstPoint{E}
   \tkzInterLL(B,S)(D,E) \tkzGetPoint{F}
   \tkzDrawPoints(D,E,F,S)
   \tkzDrawSegments[thick,red](D,E)
   \tkzDrawSegments[thick,violet](B,F)
   \tkzLabelPoints[left](D)
   \tkzLabelPoints[above left](C,F)
   \tkzLabelPoints[below right](B)
   \tkzLabelPoints[below left](A,S)
   \tkzLabelPoints[above right](E)
   \tkzMarkAngle[size=0.4 cm](B,F,E)
   \tkzLabelAngle[pos=0.6](B,F,E){\large $x$}
   \tkzMarkRightAngle(B,A,C)
 \end{tikzpicture}
 \end{minipage}
 \end{document}     

Using geogebra, I was able to prduce a simmilar looking image, as below

My question is. How can I transform my tikz image into looking more like the geogebra image? The point in S should be black, not violet, and one should keep the angle A. (I had problems both changing the color of the inscribed circle, changing the size of the labels, and changing the color of the points.)

I think that was it for now. Alas the tikz image works better without the minipages.

Answer 1

You could use options when drawing, such as

\tkzDrawCircle[R,very thick](S,\rSN pt)
\tkzDrawPoints[color=black,shape=circle,fill=black](D,E,F,S)

or set styles, such as by \tkzSetUpPoint and \tkzSetUpLine, which are explained in the tkz-euclide manual.

Regarding the labels, you could set their style via an option to the tikzpicture or by \tikzset, such as

\begin{tikzpicture}[scale=1.5,label style/.style={font=\Large}]

By this, the picture changes to

Answer 2

Stefan'answer is correct. I would like only elaborate some methods. First you can use generally most of the tikz's options, then specific macro for an object (here points) have two versions : tkzDrawPoint,and tkzDrawPoints. If all points use the same style (this is recommended) then you can use tkzDrawPoints else you need to use the first version. Finally I prefer to draw the points at the end of the code.

With your code the result is :

\documentclass{article}
 \usepackage{tkz-euclide}
 \usetkzobj{all}
 \begin{document}
 \begin{tikzpicture}[scale=1.5]
   \tkzInit[ymin=-1,ymax=5,xmin=-1,xmax=5]
   \tkzClip 
   \tkzDefPoint(0,0){A}
   \tkzDefPoint(4,0){B}
   \tkzDefPoint(0,4){C}
   \tkzDefCircle[in](A,B,C)
   \tkzGetPoint{S}
   \tkzGetLength{rSN}
   \tkzDrawPoints(A,B,C)
   \tkzDrawCircle[R](S,\rSN pt)
   \tkzDrawPolygon[very thick](A,B,C)
   \tkzInterLC[R](A,C)(S,\rSN pt) \tkzGetFirstPoint{D}
   \tkzInterLC[R](B,C)(S,\rSN pt) \tkzGetFirstPoint{E}
   \tkzInterLL(B,S)(D,E) \tkzGetPoint{F}
   \tkzDrawSegments[thick,red](D,E)
   \tkzDrawSegments[thick,violet](B,F)
   \tkzLabelPoints[left](D)
   \tkzLabelPoints[above left](C,F)
   \tkzLabelPoints[below right](B)
   \tkzLabelPoints[below left](A,S)
   \tkzLabelPoints[above right](E)
   \tkzMarkAngle[size=0.4 cm](B,F,E)
   \tkzLabelAngle[pos=0.6](B,F,E){\large $x$}
   \tkzMarkRightAngle(B,A,C)
   \tkzDrawPoints(D,E)      
   \tkzDrawPoint[color=black,fill=black](F)  
   \tkzDrawPoint[color=black,fill=violet](S)  
 \end{tikzpicture}
 \end{document}