Diagonal is defined as a line segment connecting any two nonadjacent vertices of a polygon, or a line segment connecting any two vertices of a polyhedron that are not on the same plane. In addition, in algebra, n-order determinant, the numbers from upper left to lower right belong to the main diagonal, and the numbers from upper left to upper right belong to the sub-diagonal.

Nature:

1, two diagonals of a square are equal and divided vertically, and each diagonal is equally divided into a set of diagonals.

2. 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.

3. The diagonal bisection of parallelogram.

4. The diagonals of the rectangle are equal and equally divided.

5. The diagonal lines of the diamond are equally divided and perpendicular to each other.