Arrows with rounded corners

\documentclass[tikz,border=3.14mm]{standalone}
\usepackage{textgreek}
\usetikzlibrary{decorations.text,arrows.meta,bending}
\pgfdeclarearrow{
  name =rtriangle,
  parameters = { \the\pgfarrowlength },
  setup code = {
    % The different end values:
    \pgfarrowssettipend{.25\pgfarrowlength}
    \pgfarrowssetlineend{-.25\pgfarrowlength}
    \pgfarrowssetvisualbackend{-.5\pgfarrowlength}
    \pgfarrowssetbackend{-.75\pgfarrowlength}
% The hull
\pgfarrowshullpoint{.3\pgfarrowlength}{0pt}
\pgfarrowshullpoint{-.5\pgfarrowlength}{.5\pgfarrowlength}
\pgfarrowshullpoint{-.5\pgfarrowlength}{-.5\pgfarrowlength} % Saves: Only the length:
    \pgfarrowssavethe\pgfarrowlength
  },
  drawing code = {
    \pgfsetroundjoin
    \pgfsetlinewidth{.1\pgflinewidth}
    \pgfpathmoveto{\pgfqpoint{.3\pgfarrowlength}{0\pgfarrowlength}}
    \pgfpathlineto{\pgfpoint{-.5\pgfarrowlength}{.47\pgfarrowlength}}
    \pgfpathlineto{\pgfqpoint{-.5\pgfarrowlength}{-.47\pgfarrowlength}}
    \pgfpathclose
    \pgfusepathqfillstroke
},
  defaults = { length = 4cm }
}
\begin{document}
\begin{tikzpicture}
\newcommand{\LineWidth}{10mm}
\newcommand{\Radius}{3cm}
\node[font=\sffamily\bfseries,scale=3.4,anchor=south] at (0,-0.1) {LEARN};
\node[font=\sffamily,scale=6,anchor=north] at (0,0.5) {6\textsigma};
\foreach \X [count=\Y] in {yellow!50!orange,gray!50,cyan!50,gray,red}
{\draw[line width=\LineWidth,\X] ({90-(\Y-1)*72}:\Radius)
 arc({90-(\Y-1)*72}:{90-(\Y)*72}:\Radius);}
%`,width={1.5*\LineWidth}
\foreach \X [count=\Y] in {yellow!50!orange,gray!50,cyan!50,gray,red}
{\draw[-{rtriangle[bend,length={1.5*\LineWidth}]},
line width=\LineWidth,\X]
({90-(\Y-0.5)*72}:\Radius)
 arc({90-(\Y-0.5)*72}:{90-(\Y)*72-15}:\Radius);}

\foreach \X [count=\Y] in {Define,Measure,Analyze,Improve,Control}
{\ifnum\Y=3
\fill[decoration={text along path, text={|\Large\bfseries| \X},
  raise=-3pt,text color=white,text align=center},decorate]
  ({90-(\Y)*72}:\Radius)
 arc({90-(\Y)*72}:{90-(\Y-1)*72}:\Radius);
\else
\fill[decoration={text along path, text={|\Large\bfseries| \X},
  raise=-3pt,text color=white,text align=center},decorate]
  ({90-(\Y-1)*72}:\Radius)
 arc({90-(\Y-1)*72}:{90-(\Y)*72}:\Radius);
\fi }

\end{tikzpicture}
\end{document}