Quadrilateral calculator

Calculator and formulas for calculating the properties of a quadrilateral

Quadrilateral properties calculator


This function calculates various properties of a general quadrilateral.

To calculate, enter the lengths of 3 sides and the two angles that connect these sides. Then click on the 'Calculate' button.


Quadrilateral calculator

 Input
Side length a
Side length b
Side length c
Angle β
Angle γ
Decimal places
 Results
Side length d
Diagonal e
Diagonal f
Area A
Perimeter P
Angle α
Angle δ
Viereck

Formulas of a quadrilateral


Diagonal e

\(\displaystyle e =\sqrt{a^2+b^2-2ab·cos(β)} \)

Diagonal f

\(\displaystyle f =\sqrt{b^2+c^2-2bc·cos(γ)} \)

Area A

\(\displaystyle A=\frac{\sqrt{4e^2f^2-(b^2+d^2-a^2-c^2)^2}}{4}\)

Perimeter P

\(\displaystyle P=a+b+c+d\)

Angle α

\(\displaystyle α=arccos\left(\frac{a^2+d^2-f^2}{2ad} \right)\)

Angle δ

\(\displaystyle δ=360°-α-β-γ\)


Side length d

\(\displaystyle d=\sqrt{c^2+e^2-2ce·cos(γ_2)}\)

\(\displaystyle γ_2=γ-γ_1\)

\(\displaystyle γ_1=arcos\left(\frac{b^2+e^2-a^2}{2be}\right)\)

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