Respuesta :

Answer:

option b

Step-by-step explanation:

sine all sides of a square are equal, AD = 8 too

therefore with pythagoras theorem,

AD^2 + AB^2 = BD^2

8^2 + 8^2 = BD^2

64 + 64 = BD^2

128 = BD^2

BD = root of 128 = 8 root 2 (b option)