In my country people also say idiotic things, I just dont repeat them.
You are not stupid, you are just deeply uninformed apparently.
Nothing wikipedia can't solve: https://en.wikipedia.org/wiki/Triangle
https://uk.wikipedia.org/wiki/%D0%A2%D1%80%D0%B8%D0%BA%D1%83%D1%82%D0%BD%D0%B8%D0%BA