abstract class Figure {
    getArea(): void{
        console.log("Not Implemented")
    }
    abstract getColor(): void // {} <<<<<<<<<<<<<<
}
class Rectangle extends Figure{
  getColor() {
    console.log('is red');
  }
}

// const f = new Figure(); // error
const r = new Rectangle();
console.log(r)
r.getArea();
r.getColor();