Answer:
U ={ Parallelograms}
A= { Parallelogram with four congruent sides}={ Rhombus,Square}
B ={ Parallelograms with four congruent angles} ={ Rectangle, Square}
So, AB= { Square}
So among all the parallelograms "Square" is the only parallelogram which has all congruent sides as well as all congruent angles.
Answer:
Closure property
Step-by-step explanation:
The closure property of polynomials for addition says that, if we add any two polynomials , the result is also a polynomial.
For is

is a polynomial.

is also a polynomial.
The sum of the two polynomials is

The result:

is also a polynomial.
Answer:18 weeks
Step-by-step explanation: