Quadrilateral is any closed geometric figure with four straight sides. Concave and Convex are two types which depends on how the sides of a quadrilateral are connected to one another. It is also known as a Tetragon or Quadrangle. It can be of many types such as square, rectangle, trapezoid, parallelogram, rhombus and so on. The Area of a Quadrilateral formula given here is to find the area of Quadrangle. Their diagonals with consecutive sides a, b, c, d are perpendicular if a^{2}+c^{2}=b^{2}+d^{2}.

# Area of a Quadrilateral Formula

#### Formula:

Area (S) = √[((s-a) x (s-b) x (s-c) x (s-d)) - (a x b x c x d x cos^{2}(θ/2))]

**Where,**

s = (a+b+c+d) /2

θ = θ_{1} + θ_{2}

The area of a Quadrilateral or Quadrangle formula is based on its consecutive sides where its types of rectangle, parallelogram, trapezoid are calculated from its base and height.