il give brainliest thanks

Answer:
D) a = 14, b = 6√2
Step-by-step explanation:
The given figure is trapezoid.
When we draw perpendicular to base "a", we get h = 6
From 45, 45, 90 degrees triangle, the ratio of sides 1:1:√2
since h = 6, b = 6√2
a = 8 + 6
a= 14
Therefore, a = 14 and b = 6√2
Thank you.