@nour.m
if you mean here:
http://freetexthost.com/l5wzgtntzb
than no, you did not make the changes @aha_1980 told you to do
SOURCES += main.cpp
mainwindow.cpp
my_polyhedron.cpp
myqglwidget.cpp
HEADERS += mainwindow.h
My_CGAL_Config.h
My_Face_base.h
My_Halfedge_base.h
my_polyhedron.h
My_Vertex_base.h
myqglwidget.h
still mising \ at the end of the line
also you are adding the widgets module twice. I'm not sure in what that will result, but you should remove one
QT += core gui
QT += widgets //remove me
DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x000000
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
