Ttdfjt

I'm working in a project for university using latex and i'll make a gif explaning the radians of math! And I really dont know how to make this type of line (i'll put the example below) !! Plz help me guys!!

The project that ive done so far :D
http://www.mediafire.com/file/wc4xazt8k4h4t5h/testeAnime.pdf/file

WHAT IVE DONE :D

documentclass[border=1cm]standalone
usepackage[utf8]inputenc
usepackagetikz
begindocument

begintikzpicture





beginscope
draw (0,0) circle (10cm);
draw[line width=0.15cm, blue] (10,0) arc (0:360:10) ;

draw[-] (-12,0) -- (12,0) node[right] $x$;
draw[-] (0,-12) -- (0,12) node[above] $y$;
draw[line width=0.15cm,red] (0,0) -- (10,-0);
node[scale=15.5, red, right, opacity=0.5] at (2,2) r;

draw[red][fill] (0,0) circle (0.2cm);
draw[red][fill] (10,-0) circle (0.2cm);


 endscope


endtikzpicture

enddocument

If you wish to produce such animated gifs, you may want to compile

documentclass[border=1cm,tikz]standalone
usetikzlibraryarrows.meta
begindocument
foreach X in 180,175,...,90
begintikzpicture
beginscope
draw (0,0) circle (10cm);
draw[line width=0.15cm, blue] (10,0) arc (0:360:10) ;
draw[-] (-12,0) -- (12,0) node[right] $x$;
draw[-] (0,-12) -- (0,12) node[above] $y$;
draw[line width=0.15cm,red,Circle-Circle,shorten >=-2*pgflinewidth,shorten
<=-2*pgflinewidth] (10,0) -- ++(X:10);
node[scale=15.5, red, right, opacity=0.5] at (2,2) r;
endscope
endtikzpicture
enddocument

with pdflatex and then convert the resulting pdf with

convert -density 300 -delay 34 -loop 0 -alpha remove outfile.pdf ani.gif

to get

When you attempt to patch several of those together, you want to define some command which behaves similarly as the beamer command only.

documentclass[border=1cm,tikz]standalone
usetikzlibraryarrows.meta
defOnly<#1-#2>#3ifnumnumexprX+1>#1
ifnumnumexprX-1<#2
pgfmathtruncatemacroDeltaXX+1-#1
xdefDeltaXDeltaX
#3
fifi
begindocument
pgfmathtruncatemacroXmax50
foreach X in 0,1,...,Xmax
begintikzpicture[fat line/.style=line width=0.15cm,red,Circle-Circle,shorten >=-2*pgflinewidth,shorten
<=-2*pgflinewidth,cc/.style=line width=0.15cm,
blue,annot/.style=scale=15.5]
draw[-] (-12,0) -- (12,0) node[right] $x$;
draw[-] (0,-12) -- (0,12) node[above] $y$;
%
Only<2-5>
draw[fat line] (0,0) -- (2*X,0);

Only<6-10>
draw[fat line] (0,0) -- (10,0) node[midway,above,annot,red]$r$;

Only<11-25>
typeoutDelta=DeltaX
draw[cc] (10,0) arc[start angle=0,end angle=DeltaX*24,radius=10];
draw[fat line] (0,0) -- (DeltaX*24:10);

Only<26-Xmax>
draw[cc] circle[radius=10cm];

Only<26-35>draw[fat line] (10,0) -- ++ (180-DeltaX*9:10);
Only<36-45>draw[fat line] (10,0) arc(0:18*DeltaX/pi:10) -- ++
(18*DeltaX/pi+90:10-DeltaX);
Only<46-50>
draw [fill=green!70!black,fill opacity=0.2] (0,0) -- (3,0) 
node[green!70!black,below,annot,opacity=1]rad arc[start angle=0,
end angle=180/pi,radius=3] -- cycle;
draw[cc,green!70!black] (10,0) -- (0,0) 
-- (180/pi:10);

endtikzpicture
enddocument

A PSTricks solution only for fun purposes.

documentclass[pstricks,border=12pt,12pt]standalone
radians
defobj#1%
beginpspicture(-4,-4)(4,4)
 pscircle4
 pssetlinecolor=red,linewidth=2pslinewidth
 psarc(0,0)40#1
 rput#1(4;#1)psline(!0 1 #1 sub 4 mul)
endpspicture
begindocument
 foreach i in 0,0.1,...,1.0obji
enddocument