3 Edits thanks to Gilles

## TeX/TikZ, 128121121 112 bytes

\input tikz.tex
\nopagenumbers
tikz\footline{}\tikz\draw[draw=none,fill=red](0,1)\foreach\i\foreach~ in{1,2,3}{[rotate=\i*120]arc[rotate=~*120]arc(0:60:\r pt)};
\bye;\bye


The code is based on this answer at TeX.se.

TeX is vector-based, so doesn't do pixels. The radius is a float with a maximum of about 15 before it hits the edge of the page. It's also not really built for commandline input, so need to be run as

pdftex  "\def\r{2} \input rt.tex"


where the code above is saved in rt.tex

## TeX/TikZ, 128121 bytes

\input tikz.tex
\nopagenumbers
\tikz\draw[draw=none,fill=red](0,1)\foreach\i in{1,2,3}{[rotate=\i*120]arc(0:60:\r)};
\bye


The code is based on this answer at TeX.se.

TeX is vector-based, so doesn't do pixels. The radius is a float with a maximum of about 15 before it hits the edge of the page. It's also not really built for commandline input, so need to be run as

pdftex  "\def\r{2} \input rt.tex"


where the code above is saved in rt.tex

## TeX/TikZ, 128121 112 bytes

\input tikz\footline{}\tikz\draw[draw=none,fill=red](0,1)\foreach~ in{1,2,3}{[rotate=~*120]arc(0:60:\r pt)};\bye


The code is based on this answer at TeX.se.

TeX is vector-based, so doesn't do pixels. The radius is a float with a maximum of about 15 before it hits the edge of the page. It's also not really built for commandline input, so need to be run as

pdftex  "\def\r{2} \input rt.tex"


where the code above is saved in rt.tex

2 scaling factor not needed

## TeX/TikZ, 128128 121 bytes

\input tikz.tex
\nopagenumbers
\tikz\draw[draw=none,fill=red](0,1)\foreach\i in{1,2,3}{[rotate=\i*120]arc(0:60:\r*sqrt 3\r)};
\bye


The code is based on this answer at TeX.se.

TeX is vector-based, so doesn't do pixels. The radius is a float with a maximum of about 915 before it hits the edge of the page. It's also not really built for commandline input, so need to be run as

pdftex  "\def\r{2} \input rt.tex"


where the code above is saved in rt.tex

## TeX/TikZ, 128 bytes

\input tikz.tex
\nopagenumbers
\tikz\draw[draw=none,fill=red](0,1)\foreach\i in{1,2,3}{[rotate=\i*120]arc(0:60:\r*sqrt 3)};
\bye


The code is based on this answer at TeX.se.

TeX is vector-based, so doesn't do pixels. The radius is a float with a maximum of about 9 before it hits the edge of the page. It's also not really built for commandline input, so need to be run as

pdftex  "\def\r{2} \input rt.tex"


where the code above is saved in rt.tex

## TeX/TikZ, 128 121 bytes

\input tikz.tex
\nopagenumbers
\tikz\draw[draw=none,fill=red](0,1)\foreach\i in{1,2,3}{[rotate=\i*120]arc(0:60:\r)};
\bye


The code is based on this answer at TeX.se.

TeX is vector-based, so doesn't do pixels. The radius is a float with a maximum of about 15 before it hits the edge of the page. It's also not really built for commandline input, so need to be run as

pdftex  "\def\r{2} \input rt.tex"


where the code above is saved in rt.tex

1

## TeX/TikZ, 128 bytes

\input tikz.tex
\nopagenumbers
\tikz\draw[draw=none,fill=red](0,1)\foreach\i in{1,2,3}{[rotate=\i*120]arc(0:60:\r*sqrt 3)};
\bye


The code is based on this answer at TeX.se.

TeX is vector-based, so doesn't do pixels. The radius is a float with a maximum of about 9 before it hits the edge of the page. It's also not really built for commandline input, so need to be run as

pdftex  "\def\r{2} \input rt.tex"


where the code above is saved in rt.tex