1>TestProject.obj : error LNK2019: unresolved external symbol "public: __thiscall Quadrilateral::Quadrilateral(void)" (??0Quadrilateral@@QAE@XZ) referenced in function _main
1>TestProject.obj : error LNK2019: unresolved external symbol "public: __thiscall Quadrilateral::Quadrilateral(class std::basic_string<char,struct std::char_traits,class std::allocator >,class Point,class Point,class Point,class Point)" (??0Quadrilateral@@QAE@V?$basic_string@DU?$char_traits@D@std@@v?$allocator@D@2@@std@@VPoint@@111@Z) referenced in function _main
1>TestProject.obj : error LNK2019: unresolved external symbol "class std::basic_ostream<char,struct std::char_traits > & __cdecl operator<<(class std::basic_ostream<char,struct std::char_traits > &,class Quadrilateral &)" (??6@YAAAV?$basic_ostream@DU?$char_traits@D@std@@@std@@AAV01@AAVQuadrilateral@@@z) referenced in function _main
1>C:\Users\Ahmad Anis\source\repos\TestProject\Debug\TestProject.exe : fatal error LNK1120: 3 unresolved externals
1>TestProject.obj : error LNK2019: unresolved external symbol "public: __thiscall Quadrilateral::Quadrilateral(void)" (??0Quadrilateral@@QAE@XZ) referenced in function _main
1>TestProject.obj : error LNK2019: unresolved external symbol "public: __thiscall Quadrilateral::Quadrilateral(class std::basic_string<char,struct std::char_traits,class std::allocator >,class Point,class Point,class Point,class Point)" (??0Quadrilateral@@QAE@V?$basic_string@DU?$char_traits@D@std@@v?$allocator@D@2@@std@@VPoint@@111@Z) referenced in function _main
1>TestProject.obj : error LNK2019: unresolved external symbol "class std::basic_ostream<char,struct std::char_traits > & __cdecl operator<<(class std::basic_ostream<char,struct std::char_traits > &,class Quadrilateral &)" (??6@YAAAV?$basic_ostream@DU?$char_traits@D@std@@@std@@AAV01@AAVQuadrilateral@@@z) referenced in function _main
1>C:\Users\Ahmad Anis\source\repos\TestProject\Debug\TestProject.exe : fatal error LNK1120: 3 unresolved externals