If a rectangle has four congruent sides, it is a square.
A square has perpendicular diagonals.
Conclusion: A rectangle has diagonals that are always perpendicular.
Which of the following is correct
The conclusion is valid by the law of syllogism.
The conclusion is invalid because not all rectangles are squares.
The conclusion is valid by the law of detachment.
The conclusion is invalid because all rectangles are squares.
1 answer
Invalid, all not squares
1 answer