If a shape is a parallelogram, then the shape has four sides.
If a shape has four sides, then it is a quadrilateral.
Therefore, if a shape is a parallelogram, then it is a quadrilateral.
A. Is this a valid argument?
Yes.
B. Explain why or why not.
A parallelagram has one set of sides that are parallel, and four sides. The first statement is true.
The second statement is also true. A quadrilateral is any four sided polygram. It may or may not have parallel sides.
The third statement is true because a parallelagram is a quadrilateral with two parallel sides.