There are several formulas for calculating the area of a rhombus. The most common is through the two diagonals of the rhombus (the diagonals of a rhombus are perpendicular).
The area is half the product of the diagonals (D and d).
Another way to calculate the area of a rhombus is by using the formula for the area of a parallelogram.
In this case, one side (a) is considered the base of the rhombus. The height (h) relative to said base is measured, so that the area will be the product of the base and the height.
This calculator will help you solve rhombus areas really fast without the need of doing everything by hand.
Use it on your class and get good grades!