Howcome Granny Chiyo mistook Kakashi for his father Sakumo?

[Skull Knight]

Kakashi wears a mask which hide almost all his face and we saw white fang doesnt wear any mask.
Kakashi also got sharingan unlike his father.
Moreover white fang got a pony tail whereas kakashi has wht spike hairs.
so by seeing just colour of his hairs she jump into conclusion that kakashi was white fang then she might have killed/attacked Suigetsu or Jiraya or any white haired man if she had met them before.

 

[KingHashirama]

The white hair. It was a reaction on spot. ^_^. Happens.

 

[Champ]

Obviously he looks like him in height, body size, same hair, and probably voice too

 

[Neonian]

Like you said, Kakashi had a mask. His sharingan was covered so she couldn't see it, and hey people's cloth style change overtime.

 

[obito uchiha25]

shes crazy thats why

 

[Hypemaster]

She's senile what you expect

 

[Lawliet L]

what do u think about chiyo just some old hag *****h*? she knows shit so stfu...

 

[Skull Knight]

The white hair. It was a reaction on spot. ^_^. Happens.

yep but what if Jiraya was also there.

 

[Aominecchi]

Obviously he looks like him in height, body size, same hair, and probably voice too

This ^
She didn't wait to analize him it was an instant reaction

 

[Hypemaster]

what do u think about chiyo just some old hag *****h*? she knows shit so stfu...

Negativity at its finest

 

[Prime Rib]

kakashi does look like his father alot, hair color and size, plus the body build. also she had bad eye sight

 

[GenKiDama]

the hair is a pretty obvious one

 

[Scarecrow.]

It was the hair.

 

[-PK-]

Kakashi wears a mask which hide almost all his face and we saw white fang doesnt wear any mask.
Kakashi also got sharingan unlike his father.
Moreover white fang got a pony tail whereas kakashi has wht spike hairs.
so by seeing just colour of his hairs she jump into conclusion that kakashi was white fang then she might have killed/attacked Suigetsu or Jiraya or any white haired man if she had met them before.

You answered your question yourself . Sakumo can start wearing a mask too , same hair color and people can change hairstyles over time . His sharingan was covered so she didnt see it . So shee mistook it .
I dont think it matters too much .
The old lady just got emotional after she found out the one who attacked kankuro was sasori and the old memories came back how sasori was left an orphan

 

[bogosixone]

Duh their father and sons LOL