In a parallelogram ABCD the value of 

A quadrilateral which has one pair of opposite sides parallel is called a

The sum of the lengths of all the four sides of a quadrilateral is called its

In parallelogram ABCD, its diagonals intersect at 'O'. If AO= 5 cm then AC= 

The diagonals of  a ________ are equal.

In trapezium ABCD, 

The quadrilateral in which the diagonals bisect each other and they are perpendicular to each other. 

Sum of exterior angles of a quadrilateral in right angles 

A parallelogram in which two adjacent sides are equal is a 

In a rhombus ABCD, its diagonals intersect at 'O'. Then AOB=