i have seen it several times in peoples answers where they say if a snake is poisonous its head will be trianguarly shaped...but is'nt the black mamba venomous....and if my memory is correct i dont think they have a triangle head i aint positive though....why is that referred to venomous snakes when it aint correct?
why is it said that ALL venomous snakes are triangularly shaped***

i am very familiar with snakes....i am just asking why people use this reference that all venomous snakes have triangular heads when it aint true