If it is a quadrilateral it cannot be "not a quadrilateral"!
None. A quadrilateral cannot be similar to any triangle.
No, it cannot.
It cannot. There is no way to draw a quadrilateral where 3 sides are congruent.
A quadrilateral cannot have only three vertices.
A diamond, such as a symbol in playing cards, is a quadrilateral. A diamond, as a form of carbon, is a 3-dimensional object and so cannot be a quadrilateral.
Impossible. You cannot have an obtuse angle without an acute angle in a quadrilateral.
Yes providing that the face of the door has 4 sides
A quadrilateral cannot have just 3 lines of symmetry. If it has three, then it must have 4 and is a square.
It cannot exist. By definition, a quadrilateral only has 4 sides (from the word "quad" meaning 4)
If a figure has four sides, then it is a quadrilateral; it cannot be a triangle.
Yes it can because a quadrilateral is the general term given for any 4 sided shape.