/tmp/ex3-fec0a7.o: In function `ex3()':
ex3.cpp:(.text+0x104): undefined reference to `Car::Car()'
ex3.cpp:(.text+0x10c): undefined reference to `Car::draw()'
ex3.cpp:(.text+0x12f): undefined reference to `Point::Point(double, double)'
ex3.cpp:(.text+0x13a): undefined reference to `Car::move(Point)'
ex3.cpp:(.text+0x142): undefined reference to `Point::~Point()'
ex3.cpp:(.text+0x14a): undefined reference to `Car::draw()'
ex3.cpp:(.text+0x164): undefined reference to `Trapezium::~Trapezium()'
ex3.cpp:(.text+0x171): undefined reference to `Circle::~Circle()'
ex3.cpp:(.text+0x17b): undefined reference to `Circle::~Circle()'
ex3.cpp:(.text+0x183): undefined reference to `Rectangle::~Rectangle()'
ex3.cpp:(.text+0x1f1): undefined reference to `Point::~Point()'
ex3.cpp:(.text+0x203): undefined reference to `Trapezium::~Trapezium()'
ex3.cpp:(.text+0x210): undefined reference to `Circle::~Circle()'
ex3.cpp:(.text+0x21a): undefined reference to `Circle::~Circle()'
ex3.cpp:(.text+0x222): undefined reference to `Rectangle::~Rectangle()'
clang: error: linker command failed with exit code 1 (use -v to see invocation)