Thanks, Fairlane12. Please do not read this as an adult's rebuke to you. I am 53, & have yet to stop learning new things. I was 12 once, & know how I felt about it. I can relate to your perspective because I was once your age, though that was long ago.
I know nothing of the situation other than what I read on this thread, so bear in mind that my opinions may be based on incomplete or misunderstood information. Though I empathize with the helpless dog's situation, as I understand it, the authorities deemed the dog to be viscous. Why the dog became viscous is not their concern, only that it is viscous. It was not their responsibility to rehabilitate the dog, but only to ensure the safety of the residents.
As a kid, you may not agree with this, but that is what growing up is all about. Your priorities will change as you mature; they may continue to change throughout your life. Please accept this, I know you probably think of yourself as old enough to decide for yourself what to do with you life, & resent adults telling what to do, but 2 or 3 years from now, you may look back at yourself at age 12, & realize just how little you did know. I myself can state that I did not grow up until about age 30.
As long as you think you have arrived, you will remain a long way from it. Once you realize that you never finish the maturation process, you will have made progress. It never ends.
Looking at your 1st post, I am a bit confused; you state that the dog's mere resemblance to a PIT BULL was the reason they killed him, then in parenthesis, you noted the dog's mistreatment for the past two years. Thus, I am unsure of the council's exact reason for its decision. Perhaps you can restate your 1st post, as I think you were rushed when you wrote it.