Draw the largest circle in the square (the inscribed circle of the square), and the area of this circle is about 78.5% [4 π] of the square area; The area of the smallest circle (circumscribed circle of a square) that completely covers a square is about 157% [π] of the square area. ? A square is a special rectangle and a square is a special diamond. ?

The trial in the square:

1, the rhombus with equal diagonal lines is a square.

2. Diamonds with right angles are squares.

3. A rectangle with diagonal lines perpendicular to each other is a square.

4. A set of rectangles with equal adjacent sides is a square.