i just started qt programming after finishing the first tutorial i run(as the tutorial said)
qmake -project
qmake
then it created a make file to my programme which is in main.cpp
then i run make and it said it could not find the include files
<qapplication.h>
<qpushbutton.h>
i know they are installed check with locate
how can i solve this problem and this is the code that i am trying to compile

/****************************************************************
**
** Qt tutorial 1
**
****************************************************************/

#include <qapplication.h>
#include <qpushbutton.h>


int main( int argc, char **argv )
{
QApplication a( argc, argv );

QPushButton hello( "Hello world!", 0 );
hello.resize( 100, 30 );

a.setMainWidget( &hello );
hello.show();
return a.exec();
}