/tmp/ex3-44fb8c.o: In function `ex3()':
ex3.cpp:(.text+0xe5): undefined reference to `Point::Point(double, double)'
ex3.cpp:(.text+0x107): undefined reference to `Car::Car()'
ex3.cpp:(.text+0x113): undefined reference to `Car::draw()'
ex3.cpp:(.text+0x13f): undefined reference to `Point::Point(double, double)'
ex3.cpp:(.text+0x14a): undefined reference to `Car::move(Point)'
ex3.cpp:(.text+0x152): undefined reference to `Point::~Point()'
ex3.cpp:(.text+0x15a): undefined reference to `Car::draw()'
ex3.cpp:(.text+0x173): undefined reference to `Trapezium::~Trapezium()'
ex3.cpp:(.text+0x17f): undefined reference to `Circle::~Circle()'
ex3.cpp:(.text+0x188): undefined reference to `Circle::~Circle()'
ex3.cpp:(.text+0x190): undefined reference to `Rectangle::~Rectangle()'
ex3.cpp:(.text+0x1b7): undefined reference to `Point::~Point()'
ex3.cpp:(.text+0x226): undefined reference to `Point::~Point()'
ex3.cpp:(.text+0x238): undefined reference to `Trapezium::~Trapezium()'
ex3.cpp:(.text+0x244): undefined reference to `Circle::~Circle()'
ex3.cpp:(.text+0x24d): undefined reference to `Circle::~Circle()'
ex3.cpp:(.text+0x255): undefined reference to `Rectangle::~Rectangle()'
ex3.cpp:(.text+0x284): undefined reference to `Point::~Point()'
clang: error: linker command failed with exit code 1 (use -v to see invocation)