Answer:
a=22
Explanation:
a-1. 5 =20. 5 ( opposite side of parallelogram are equal )
or, a=20. 5+1. 5
or, a=22
you can do it from another side too.
2a-20. 8 = a + 1. 2 ( opposite side of parallelogram are equal )
or, 2a - a = 1. 2 + 20. 8
or, a = 22
Hope it will help you ☺✌