Answer:
Part A)


Part B)


Explanation:
we know that
In a parallelogram, the opposite angles and opposite sides are congruent, and consecutive angles are supplementary
Part A)
we know that
----> by opposite angles
----> by opposite angles
-----> by consecutive angles
we have

Find the value of m<L


therefore

Part B)
we know that
----> by opposite sides
----> by opposite sides
we have


therefore

