A quadrilateral is a type of polygon that has four corners and sides. It is called a parallelogram (rectangle, square, or rhombus) when its diagonals bisect to each other.
True
I think this is impossible the diagonals of a four sided figure will cross
True
always
true
The missing word is "bisect".
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.
The answer is no the diagonals do not have to bisect each other. That does not necessarily mean that there isn't a quadrilateral that has bisecting diagonals. A quadrilateral is a four-sided polygon which is a close plane figure; in this case with four sides. Meaning that all ends of the straight lines that configure a polygon must connect someway, somehow.
Square
diagonals.
True
Square, Rhombus