<<VilGebra`

P={3,4,5};
GraficaPuntos3D[{P}]

P={3,4,5};
Pxy={3,4,0}; 
Px={3,0,0};   
Py={0,4,0}; 
Pz={0,0,5};   
Graphics3D[{{Thick,Arrow[{{0,0,0},{4,0,0}}]},{Thick,Arrow[{{0,0,0},{0,5,0}}]},{Thick,Arrow[{{0,0,0},{0,0,6}}]},{Black,Text["x",{4.2,0,0}]},{Black,Text["y",{0,5.2,0}]},{Black,Text["z",{0,0,6.2}]},{Red,PointSize[0.02],Point[P]},{Red,Text["P(3,4,5)",P+{0.3,0.3,0.3}]},{Blue,PointSize[0.015],Point[Pxy]},{Blue,PointSize[0.015],Point[Px]},{Blue,PointSize[0.015],Point[Py]},{Blue,PointSize[0.015],Point[Pz]},{Gray,Dashing[{0.02}],Line[{P,Pxy}]},{Gray,Dashing[{0.02}],Line[{P,Pz}]},{Gray,Dashing[{0.02}],Line[{Pxy,Px}]},{Gray,Dashing[{0.02}],Line[{Pxy,Py}]},Table[{Black,Line[{{i,0,0},{i,0,0.1}}]},{i,1,3}],Table[{Black,Line[{{0,j,0},{0,j,0.1}}]},{j,1,4}],Table[{Black,Line[{{0,0,k},{0.1,0,k}}]},{k,1,5}]},Axes->False,BoxRatios->{1,1,1},ViewPoint->{2,-2,1},ImageSize->400,Background->White,Lighting->"Neutral"]