Extended data:
Nature of the square:
1, two groups of opposite sides are parallel respectively; All four sides are equal; Adjacent sides are perpendicular to each other.
2. All four angles are 90, and the sum of internal angles is 360.
3. Diagonal lines are perpendicular to each other; Diagonal lines are equal and equally divided; Each diagonal bisects a set of diagonal lines.
4. It is both a central symmetrical figure and an axisymmetric figure (with four axes of symmetry).
5. A diagonal line of the square divides the square into two isosceles right triangles, and the included angle between the diagonal line and the side is 45; The two diagonal lines of a square divide it into four congruent isosceles right-angled triangles.
6. A square has all the properties and characteristics of parallelogram, rhombus and rectangle.
7. 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.
8. A square is a special rectangle and a square is a special diamond.
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