A field initializer cannot reference the nonstatic field, method, or property

Hi, I searched on the internet about this problem but the answers didn’t help, so I’d like to ask you how to avoid this error. (I’m a beginner so please don’t lynch me if it’s a stupid question xD).
I’ve created a class (Figure) which has a name, an int order and a transform and it has a constructor to give each figure its name and transform.

public class Figure
        public int order;
        public string name;
		public Transform tr;
		public Figure(string name_, Transform tr_)
            this.name = name_; 
			this.tr = tr_;

I’ve declared 4 public transforms that I give to 4 figures, and then I created an array that I’ll use later with those figures.

	public Transform SquareTR;
	public Transform TrapezoidTR;
	public Transform CircleTR;
	public Transform TriangleTR; 

	Figure SquareF = new Figure("Square", SquareTR);
	Figure TrapezoidF = new Figure("Trapezoid", TrapezoidTR);
	Figure CircleF = new Figure("Circle", CircleTR);
	Figure TriangleF = new Figure("Triangle", TriangleTR);

	Figure[] Figures = { SquareF, TrapezoidF, CircleF, TriangleF };
    rest of the code...

When I start the game, the error occurs: “A field initializer cannot reference the non static field, method, or property”, for each transform and figure.
I could fix this problem creating the figures in the Start() function, but I have to use them in the Update() function too.
I could also make figures and transforms static, but I have to assign the transforms from the inspector (If I don’t do that the NullReferenceException pops up).
How can I fix this problem?

You’re assigning CircleF and SquareF directly. Keep both variables there, but do the creations and assignments in Awake. Constructors must not be called for fields directly.