Question

Premises:
If a quadrilateral has two pairs of parallel sides, then it is a parallelogram.
If a quadrilateral is a parallelogram, then its opposite angles are congruent.

Conclusion:
If a quadrilateral has two pairs of parallel sides, then its opposite angles are congruent.



Which statement best describes this argument?

The argument is valid by the law of detachment.

The argument is invalid because the conclusion does not follow the premises.

The argument is invalid because the premises are not true.

The argument is valid by the law of syllogism.