Rhombus

A rhombus is an equilateral quadrangle, which is an equilateral having four sides of equal length. It looks like a diamond.

Its area is the product of its diagonals divided by two. Note that its diagonals are perpendicular to each other, and bisect each other.

In symbolic form, the area of a rhombus having diagonals of lengths D₁ and D₂ is:

$A={\frac {D_{1}\times D_{2}}{2}}$

This area also equals the length of a side (B) multiplied by the length of the perpendicular between two opposite sides (H):

$A=B\times H$