C/C++ :: How To Save Triangles / Polylines Into Vector Using New Keyword

In C++ by FLTK, to define a circle we use some code like this:

Circle c(Point(x,y), r);

And we can using vector_ref put and save them in a vector, like:

Vector_ref<Circle> vc;
vc.push_back(new Circle(Point(x,y),r));

Ok, those were about Circle and no problem till now!

Triangle can be defined like this for using in codes:

Graph_lib::polyline poly;
poly.add(Point(x1,y1),r1);
poly.add(Point(x2,y2),r2);
poly.add(Point(x3,y3),r3);

and this is a vector to saving them:

Vector_ref<Graph_lib::Polygon> vp;

The problem is that how to save/put triangles/polylines into that vp vector using new keyword like the circle does?

My sig: Save Cobani.