Given a JSON object, write a python program to print the square of every value, only if the value is even.
{
 "a": 1,
 "b": 2,
 "c": 3,
 "d": 4
}
import json

data = {
 "a": 1,
 "b": 2,
 "c": 3,
 "d": 4
}

for key, value in data.items():
 if value % 2 == 0:
 print(value**2)