Look at the statement below.

“All squares are quadrilateral.”

Which of these is a logically equivalent statement?

If it is not a square, it is not a quadrilateral.

)All quadrilaterals are squares.

)If it is not a quadrilateral, it is not a square.

)It will be a quadrilateral if and only if it is square.

Question

Look at the statement below.
 
“All squares are quadrilateral.”
 
Which of these is a logically equivalent statement? 

If it is not a square, it is not a quadrilateral.

)All quadrilaterals are squares.

)If it is not a quadrilateral, it is not a square.

)It will be a quadrilateral if and only if it is square.

parthkohli · Answer

The contrapositive will be equivalent.

parthkohli · Answer

Contrapositive of "If P then Q" is "If not Q then not P"

goformit100 · Answer

answer is c

anonymous · Answer

Usually I know the other ones of these (Converse, inverse etc.) but I wasn't sure about the logically equivilent statment.

parthkohli · Answer

@goformit100 please explain your answer

anonymous · Answer

I believe you, I just want to know how to solve it...

goformit100 · Answer

sorry friends answer is " all quad. are sqares"

goformit100 · Answer

B is the correct answer

parthkohli · Answer

No @goformit100

parthkohli · Answer

What about parallelogram? That's a quadrilateral but not a square.

parthkohli · Answer

Or a rhombus...or a kite.

anonymous · Answer

Aren't all of those quadrilaterals though?

parthkohli · Answer

Yes...and he said that all quads are squares

parthkohli · Answer

All quads are not squares.

parthkohli · Answer

Answer will be C. since it is the contrapositive

anonymous · Answer

So 'If it is not a quadrilateral, it is not a square.'?

parthkohli · Answer

Yes.

anonymous · Answer

Thank you.

anonymous · Answer

c