Fdtxjr

I want to color the edge AB with thick blue color and edges AC and BC with thick red color.

Referring to the answer in Multiple color edges in TikZ, one way is to use the clip[draw] command. But, I am not sure how to use in my context, as my shape is a triangle and the triangle is filled with orange color as well.

Expected Result:

Current Result:

The triangle should still have the orange color filled and the edges with the above mentioned color.

Note: This example is from the PGF manual only. Providing the code in the manual is not recommended/appreciated without explanation.

Is there an alternate way to fill a shape instead of using filldraw or draw[fill] command.

MWE:

documentclassarticle
usepackagetikz
usetikzlibrarycalc
usetikzlibrarythrough
usetikzlibraryintersections
begindocument
begintikzpicture[help lines/.style=thin,draw=black!50]
 coordinate[label=left:textcolorblue!80!black$A$] (A) at (0,0);
 coordinate[label=right:textcolorblue!80!black$B$] (B) at (1.25,0.25);
 draw[name path=A--B] (A) -- (B);
% draw let p1 = ($(B) - (A)$),
% n2 = veclen(x1,y1)
% in
% (A) circle (n2)
% (B) circle (n2);
 node (D) [name path=D,draw,circle through=(B),label=left:$D$,help lines,draw] at (A) ;
 node (E) [name path=E,draw,circle through=(A),label=right:$E$,help lines,draw] at (B) ;

 path [name intersections=of=D and E, by=[label=above:$C$]C,[label=below:$C'$]C'];

 %coordinate[label=above:$C$] (C) at (intersection-1); using by instead

 draw [name path=C--C',red] (C) -- (C');

 path [name intersections=of=A--B and C--C', by=F];
 node[fill=red,inner sep=1pt, label=-45:$F$] at (F) ;

 draw[fill=orange!80] (A) -- (B) -- (C) -- cycle;
 foreach point in A,B,C
 fill [black,opacity=0.5] (point) circle (2pt);
endtikzpicture
enddocument 

Some options can be applied to a portion of the path, this is the case of rounded corners. But this does not work with the colors as indicated on page 149 of manual 3.1.1 which always apply to the entire path.

Screenshot of the page 149:

So, to make it easier:

• I first colored the ABC triangle orange with the fill command (which doesn't draw anything);


• then I drew two paths, one in blue, the other in red.

Commented code:

documentclass[border=5mm]standalone
usepackagetikz
usetikzlibrarycalc
usetikzlibrarythrough
usetikzlibraryintersections
begindocument
begintikzpicture[help lines/.style=thin,draw=black!50]
 coordinate[label=left:textcolorblue!80!black$A$] (A) at (0,0);
 coordinate[label=right:textcolorblue!80!black$B$] (B) at (1.25,0.25);
 path[name path=A--B] (A) -- (B);% <-- construct the path, but not draw it
% draw let p1 = ($(B) - (A)$),
% n2 = veclen(x1,y1)
% in
% (A) circle (n2)
% (B) circle (n2);
 node (D) [name path=D,draw,circle through=(B),label=left:$D$,help lines,draw] at (A) ;
 node (E) [name path=E,draw,circle through=(A),label=right:$E$,help lines,draw] at (B) ;

 path [name intersections=of=D and E, by=[label=above:$C$]C,[label=below:$C'$]C'];

 %coordinate[label=above:$C$] (C) at (intersection-1); using by instead

 path [name path=C--C',red] (C) -- (C');

 path [name intersections=of=A--B and C--C', by=F];
 %node[fill=red,inner sep=1pt, label=-45:$F$] at (F) ;

 fill[orange!80] (A) -- (B) -- (C) -- cycle;%<-- only fill without draw the edges
 draw[blue,thick](A)--(B);%<-- draw in blue
 draw[red,thick](A)--(C)--(B);%<-- draw in red
 foreach point in A,B,C
 fill [black,opacity=0.5] (point) circle (2pt);
endtikzpicture
enddocument 

You can save some of your paths by using the possibilities of the path or draw command. Especially the empty paths may be removed by integrating the intersections into the relevant paths.

To color your way from A to B simply draw a line between the two points (after drawing the frame or simply removing the frame). The same works for A--B--C.

documentclassarticle
usepackagetikz
usetikzlibrarycalc
usetikzlibrarythrough
usetikzlibraryintersections
begindocument
begintikzpicture[help lines/.style=thin,draw=black!50]
 path[name path=A--B] (0,0) coordinate[label=left:textcolorblue!80!black$A$] (A) --
 (1.25,0.25) coordinate[label=right:textcolorblue!80!black$B$] (B);
 node (D) [name path=D,draw,circle through=(B),label=left:$D$,help lines,draw] at (A) ;
 node (E) [name path=E,draw,circle through=(A),label=right:$E$,help lines,draw] at (B) ;
 draw[name intersections=of=D and E, by=[label=above:$C$]C,[label=below:$C'$]C',
 name path=C--C',red] (C) -- (C');
 node[fill=red,inner sep=1pt,name intersections=of=A--B and C--C', by=F,label=-45:$F$] at (F) ;

 draw[draw=none,fill=orange!80] (A) -- (B) -- (C) -- cycle;
 draw[blue,thick] (A) -- (B);
 draw[red,thick] (A) -- (C) -- (B);

 foreach point in A,B,C
 fill [black,opacity=0.5] (point) circle (2pt);
endtikzpicture
enddocument