Solution: TypeScript Inheritance

abstract class Shape {
  constructor(public name: string) {}
  abstract calculateArea(): number;
}

class Circle extends Shape {
  constructor(public radius: number, name: string) {
    super(name);
  }
  calculateArea(): number {
    return Number((Math.PI * this.radius ** 2).toFixed(2));
  }
}

class Square extends Shape {
  constructor(public sideLength: number, name: string) {
    super(name);
  }
  calculateArea(): number {
    return this.sideLength ** 2;
  }
}

class Triangle extends Shape {
  constructor(public base: number, public height: number, name: string) {
    super(name);
  }
  calculateArea(): number {
    return 0.5 * this.base * this.height;
  }
}