Which of the following conditions are necessary and sufficient for a quadrilateral to be a square?
(1)All sides are of same length
(2) All angles are equal
(3) Diagonals are perpendicular to each other
(4) Diagonals are of same length
(5) Opposite sides should be parallel
3 and 4
We can find exceptions for options (a), (b), (d) where by the conditions given we can construct a quadrilateral which is not square.
(a)All sides same length, diagonals perpendicular A Rhombus is also possible
(b)Angles equal, equal diagonals lengths A rectangle satisfies this condition.
(c)Diagonals perpendicular to each other and of same lengths.
Only a square can be constructed using this condition.
(d)Sides are equal and opposite sides are parallel.
A rhombus is possible with given condition.