Calculations for pentagon dimensions

pentagon.js

class Pentagon {
  static get SIDE_COUNT()   { return 5; };
  static get TOTAL_ANGLE()  { return 180 * (Pentagon.SIDE_COUNT - 2); };
  static get CORNER_ANGLE() { return Pentagon.TOTAL_ANGLE / Pentagon.SIDE_COUNT; };
  static get SQRT_SIDES()   { return Math.sqrt(Pentagon.SIDE_COUNT); };


  constructor (from, value) {
    if (isNaN(+from)) {
      this[from] = value;
    } else {
      this.sideLength = from;
    }
  }


  get height() { return Pentagon.height(this.sideLength); }
  get diagonalLength() { return Pentagon.diagonalLength(this.sideLength); }
  get perimeterLength() { return Pentagon.perimeterLength(this.sideLength); }
  get area() { return Pentagon.area(this.sideLength); }
  get outerRadius() { return Pentagon.outerRadius(this.sideLength); }
  get innerRadius() { return Pentagon.innerRadius(this.sideLength); }


  static sideLength(sideLength) {
    return sideLength;
  }

  static area(sideLength) {
    return (Math.pow(sideLength, 2) / 4) * Math.sqrt(10 * Pentagon.SQRT_SIDES + 25);
  }

  static height(sideLength) {
    return sideLength * Math.sqrt(5 / 4 + Pentagon.SQRT_SIDES / 2);
  }

  static outerRadius(sideLength) {
    return (sideLength / 10) * Math.sqrt(10 * Pentagon.SQRT_SIDES + 50);
  }

  static innerRadius(sideLength) {
    return (sideLength / 10) * Math.sqrt(10 * Math.sqrt(5) + 25);
  }

  static diagonalLength(sideLength) {
    return (sideLength / 2) * (1 + Pentagon.SQRT_SIDES);
  }

  static perimeterLength(sideLength) {
    return sideLength * 5;
  }


  static sideLengthFromArea(area) {
    return Math.sqrt((4 * area) / Math.sqrt(10 * Pentagon.SQRT_SIDES + 25));
  }

  static sideLengthFromHeight(height) {
    return (2 * height) / Math.sqrt(5 + 2 * Pentagon.SQRT_SIDES);
  }

  static sideLengthFromOuterRadius(outerRadius) {
    return outerRadius * Math.sqrt(10 / (5 + Pentagon.SQRT_SIDES));
  }

  static sideLengthFromInnerRadius(innerRadius) {
    return 2 * innerRadius * Math.sqrt(5 - (2 * Pentagon.SQRT_SIDES));
  }

  static sideLengthFromDiagonalLength(diagonalLength) {
    return (2 * diagonalLength) / (1 + Pentagon.SQRT_SIDES);
  }

  static sideLengthFromPerimeterLength(perimeter) {
    return perimeter / Pentagon.SIDE_COUNT;
  }
}