There are three formulas for the area of a diamond: S=ab, S=cd÷2, and s = the square of a multiplied by sinθ. On the same plane, a set of parallelograms with equal adjacent sides is a rhombus, and a quadrilateral with equal four sides is a rhombus, and the diagonal of the rhombus is vertically bisected and bisected by each set of diagonal lines. A diamond is an axisymmetric figure with two symmetrical axes, that is, the straight lines where the two diagonals are located, and a diamond is a figure with central symmetry.

A closed plane figure or three-dimensional figure surrounded by four line segments that are not on the same line is called a quadrilateral, which consists of a convex quadrilateral and a concave quadrilateral. The quadrilateral obtained by connecting the midpoints of any quadrilateral in turn is called a midpoint quadrilateral, and the midpoint quadrilateral is a parallelogram. The midpoint quadrangle of a diamond is a rectangle, the midpoint quadrangle of a rectangle is a diamond, the midpoint quadrangle of an isosceles trapezoid is a diamond, and the midpoint quadrangle of a square is a square.