in a quadrilateral ABCD find x.

Given that the vertices A, B, C of a quadrilateral ABCD lie on a circle. Also angleA + angleC = 180^@ , then prove that the vertex D also lie on the same circle.

In a quadrilateral ABCD, angleB = 90^0 , AD^2 = AB^2 + BC^2 + CD^2 . Prove that angle ACD = 90 ^0 .

One of the diagonals of the quadrilateral ABCD is

The diagonals of a quadrilateral ABCD intersect each other at point'O' such that (AO)/(BO)=(CO)/(DO) . Prove that ABCD is a trapezium.

In a quadrilateral ABCD a parallelogram, if /_A=70^@ and /_C=65^@ ? give reasons.

In a Quadrilateral ABCD, cos A.cosB + sin C sin D=

The area of any cyclic quadrilateral ABCD is given by A^(2)=(s-a)(s-b)(s-c) (s-d) , where 28 = a + b + c + d, a, b,c and d are the sides of the quadrilateral. Now consier a cyclic quadrilateral ABCD of area 1sq.unit and answer the following questions: The minimum perimeter of the quadrilateral is

If the ratio of the angles of a quadrilateral ABCD is 1:2:1:2 and the length of one side is 6 cm and perpendicular drawn to it is 4 cm. Then find the area.