Answer:
one abbreviation i have used quadrilateral = quad
and one more i am not using angle word everywhere so please understand that much
Explanation:
As quad ABCD is a cyclic quad
which means that opposite angles sum has to 180
so B + D = 180
3y+16 +6y+2 = 180
9y+18=180
9y=162
y=162/9
y= 18 (replace this value in C)
C = 4y+6 = 4*18 +6 = 72+6 = 78
from stated above
A+C= 180
A+78 = 180
A= 180-78
A = 102 degree
hope it helps