class.js

class Rectangle extends Shape {
  constructor( x, y, color ) {
    super( color );

    this.x = x;
    this.y = y;
    this.color = color
  }
  
  get length( ) {
    return x;
  }
  
  get width( ) {
    return y;
  }
  
  set color( c ) {
    this.color = c;
  }
  
  static numberOfEdges( ) {
    return 4;
  }
}