Question

“All squares are parallelograms.”

Which of the following is a sufficient condition for the above statement to be true?

A square has equal diagonals.
A square has four right angles.
A square has its opposite sides parallel.
A square has diagonals which intersect at right angles

Answer 1

In order for the statement to be true, the square has to have certain qualities that belong to a parallelograms, i.e.,:
1) it must have 4 sides;
2) it must have two pairs of parallel sides.
Since 1) is not in the option list, we must pick the condition that makes 2) true. I would pick the third one :-)

Answer 2

thank you :D

Answer 3

No problem :-)