yep i think so
diagonals.
If the diagonals of a quadrilateral are perpendicular to each other, then the quadrilateral is a square.Or a kite.
True
True
True
If you are talking about the diagonals of a quadrilateral, the only quadrilateral that have diagonals that are perpendicular and bisect each other is a square, because a rectangle has bisecting diagonals, while a rhombus has perpendicular diagonals. And a square fits in both of these categories.
always
true
The missing word is "bisect".
False maybe
The diagonals of every quadrilateral must intersect.
Parallelogram and a rectangle