Answer: BC= 18 units .
Step-by-step explanation:
Since we have given that
Diagonal of square WXYZ is given by

As we know the formula of "Diagonal of square",

Since 'A' is the midpoint of WX so,
Length of AX=YE is given by

Since AB=AC and ΔABC is right angled triangle , so,

So, In ΔCEY,

in ΔXYB,

So,
