They are mathematical oddities such as the Mobius strip.
It's called a mobius strip.
A mobius strip has only two sides. As for the general name for such a class of shapes there is none.
A line (2D), ray (2D), vector (2D), line segment (2D), a mobius strip (3D), or a klein bottle (3D).
I guess you could say that a Mobius strip is a one-sided shape. Or a circle, because there are no corners or divisions where another side starts.
mobius strip
He invented the Mobius Strip The Mobius Strip is a one sided surface. It is made my twisting a strip of paper and taping the two ends together.
The mobius strip was created in 1858 independently by August Fernandid Mobius and Johann Benedict Listing, two German mathematicans.
You will still have a mobius strip.
It was a mistake in the image placed there.
Karl Friedrich Gauss
Really clever question. What would probably happen is that the area around the joint will be neutral. It would be just like making a Mobius strip from paper that is red on one side and green on the other. The red-green joint area will be brown. The polarity of both the ends would nullify or destroy.
According to www.answers.com, a mobius strip is a continuous one-sided surface that can be formed from a rectangular strip by rotating one end 180° and attaching it to the other end.
A Mobius strip.
1780
The mobius strip.
....... to get to the same side!Explanation; one of the many answers to the joke "Why did the chicken cross the road?" is "to get to the other side." A Mobius strip is a figure that has only one side, hence the change in the answer.