The red line in the above picture is the two middle lines of a rectangle, and the intersection of the two middle lines is point O.
Quadrilateral MNPQ arbitrarily connecting m, n, p and q
According to the midline theorem.
The midpoint of MP is on the center line of rectangular ABCD.
The midpoint of QN is on the center line of rectangular ABCD.
Because MNPQ is a diamond, the midpoint of MP must coincide with the midpoint of QN and the intersection o of the bit lines in the rectangle.
2) Given a certain rectangle, let AB be the long side, and length A and length B of BC.
According to the unique area formula of diamonds.
The diagonal of the diamond is vertical. Imagine the change of e angle.
The third situation in the above picture is irrelevant. The four endpoints of the diamond should be distributed on the four sides of the rectangle respectively.
The length of AB is A, and the length of BC is B, (A is greater than or equal to B).
3) The drawing method is to connect a diagonal line of the rectangle of BD, make the intersection point of the middle vertical line of BD M, P, and connect the four points of M, N, P and Q to get the largest diamond. (where point n coincides with point b and point q coincides with point d)