Question

History of the number of rhombus​

Answer 1

Answer:

In plane Euclidean geometry, a rhombus (plural rhombi or rhombuses) is a quadrilateral whose four sides all have the same length. Another name is equilateral quadrilateral, since equilateral means that all of its sides are equal in length. The rhombus is often called a diamond, after the diamonds suit in playing cards which resembles the projection of an octahedral diamond, or a lozenge, though the former sometimes refers specifically to a rhombus with a 60° angle (which some authors call a calisson after the French sweet[1] – also see Polyiamond), and the latter sometimes refers specifically to a rhombus with a 45° angle.

Rhombus

Two rhombi

Typequadrilateral, parallelogram, kiteEdges and vertices4Schläfli symbol{ } + { }

{2α}Coxeter diagramSymmetry groupDihedral (D2), [2], (*22), order 4Area{\displaystyle K={\frac {p\cdot q}{2}}} (half the product of the diagonals)Dual polygonrectanglePropertiesconvex, isotoxal



The rhombus has a square as a special case, and is a special case of a kite and parallelogram.

Every rhombus is simple (non-self-intersecting), and is a special case of a parallelogram and a kite. A rhombus with right angles is a square.[2][3]

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