Birds and feathers?

Ok how do you feel about this statement:
All birds have feathers
If an animal is a bird then it has feathers.

My Geometry teacher told us this and said that the statement is always true,but I said what about a penguin and he said that penguins do have...

feathers and I said that it was fur.Then I said what about pterodactyls they're technically birds but didn't have feathers,and totally didn't hear me so that brings me to my point I find it interesting and would like to know what ya'll think.
Do you agree with the statement or not?

If not then give another example of a bird w/o feathers.

I don't know another bird without feathers but your geo teacher sounds like an idiot. haha

Well, first of all, you were correct. Penguins do have feathers. As did pterodactyls.

I myself have never heard of a featherless bird, but I'm sure there are some out there.

I always get in debates with teachers. In that case I would have said a plucked chicken. It's still a bird, and he said nothing about the condition. But penguins do have feathers.

kiwis don't have feathers.'

**EDIT**

neverrrmind apparently they do

all birds have feathers , just like us we have skin

http://www.truveo.com/Featherless-bird-So-ugly-its-cute/id/4056221825
check out this site...its nearly a featherless bird...its Oscar and she has a disease where when her feathers grown in it irritates her and she plucks them out!

If you pluck out all of it's feathers, it's still classified as a bird. The teacher has a faulty syllogism, that's all; it's missing an additional step.

All Birds have feathers.
An animal is not a bird if it doesn't have feathers.
Therefore, all feathered animals are birds.

Or something along those lines. Even though that's still a faulty thing to say, albeit very radically...

I don't think your teacher was talking about a bird being prepared for dinner...LOL...

He's trying to teach you something about Geometry, using a valid syllogism (not in geometric terms), to make it more understandable...

Trying to argue the syllogism (especially, with an untrue and obviously unresearched argument..."penquins have fur"... isn't going to do you any good when test time comes around...no wonder he ignored you.

phrannie

yea phrannie I know what he was talking about the lesson,he's teaching us logistics,and converse,inverse and contrapositives but It's just the bird thing that I'm interested in.
And he didn't ignore he was standing on the other side of the room when I mentioned that,and he knows I'm capable of acing his tests so he's not worried about that I just want to know bout the birds

Actually penguins do have feathers... the layer you see is not made of hair (which would make it fur) but of feathers... making your argument wrong...

Does a tomatoe classify as a bird because if it does your teechers wrong.

lol sorry: slap happy uh I agree w/ it yor staement