\input{../Triangle.tikz}
\tikzmath{\a=1;};
\tikzmath{\b=3;};
\tikzmath{\c=2;};


\coordinate (O) at (0,0);
\coordinate (P1) at (-\a,0);
\coordinate (P2) at (\b,0);
\coordinate (P3) at (0,\c);
   
\DrawPoint{(P1)}{P_1}{below};
\DrawPoint{(P2)}{P_2}{below};
\DrawPoint{(P3)}{P_3}{above};
   
\DrawTriangle{(P1)}{(P2)}{(P3)};
\DrawTriangleHeights{(P1)}{(P2)}{(P3)}{dotted};