1st net formation is 4 triangles each side of a central square.

2nd net formation is 4 equilateral triangles of the same size joined along one edge each time to form a spiralling pattern.

3rd net formation has a square with one equilateral triangle of the same side length joining one side of the square. A further two equilateral triangles of the same size are added to the first triangle each by one edge to form a spiralling pattern. A vertex of each triangle touches the top right corner of the square.

4th net formation is 4 equilateral triangles of equal size joined to form a larger equilateral triangle.