Which statement about a parallelogram is always true?

The diagonals are congruent.

The diagonals are perpendicular.

The adjacent sides are congruent.

The adjacent angles are supplementary.
is it d?

Question

Which statement about a parallelogram is always true?

 The diagonals are congruent.

 The diagonals are perpendicular.

 The adjacent sides are congruent.

 The adjacent angles are supplementary.
is it d?

anonymous · Answer

@amistre64

nathan917 · Answer

The diagonals are perpendicular..

anonymous · Answer

@mathslover

anonymous · Answer

it is option d

anonymous · Answer

How did you get D, @shrinifores?

nathan917 · Answer

This makes no sense, He asked a question b4 this and a math teacher said id way D also. so..

nathan917 · Answer

it*

ganeshie8 · Answer

it is D, by definition of parallelogram & parallel line properties

nathan917 · Answer

Yeah. im going with D.

anonymous · Answer

You know that by angle sum property of a quadrilateral the sum of the angles is 360 degree. And in a parallelogram the opposite sides have equal angles. So, if u consider the adjacent angles to be x and y, u will get 
2x+2y=360
x+y=180
So, the sum of two adjacent angles is 180. So they are supplementary

nathan917 · Answer

http://answers.yahoo.com/question/index?qid=20100330171730AAtmZmy

nathan917 · Answer

So. its D.