N

p1={{0,0},{0,3}};
g1=Graphics[{BezierCurve[p1],Blue,Point[p1]}];

p2={{3,0},{3,3}};
g2=Graphics[{BezierCurve[p2],Blue,Point[p2]}];

p3={{0,3},{3,0}};
g3=Graphics[{Red,Thick,BezierCurve[p3],Blue,Point[p3]}];

Show[g1,g2,g3]