Find the sum of the squares of the two adjacent sides of the angle which is then subtracted from the square of the opposite diagonal. H 1 and h 2 are the heights of triangles ADC and ABC respectively. The quadrilateral having one pair of opposite sides parallel to each other and other pair of sides are equal then it is called an Isosceles trapezium.
Area of the quadrilateral is the region enclosed by the four sides of this polygon.
Apply length-times-width as a formula to calculate area of regular and some irregular quadrilaterals When the length-times-width formula cannot apply find the area of irregular quadrilaterals using other strategies including the Law of Cosines and Herons Formula. The area of quadrilateral PQRS is equal to the sum of the area of triangle PSR and the area of triangle PQR. A quadrilateral is cyclicif it can be inscribed in a circlethat is if its four vertices belong to a single circumscribedcircle. Five different formulas are used to calculate the area of the quadrilateral.