Why Are There No Three Legged Animals?

Ok think of a chair. It has 4 legs so it can balance and hold itself up, or the chair (and you) would fall over. If animals had 3 legs they would always be falling over. It would be much harder to stand on 1 leg! Hope this helped!

There are no animals in nature that are three legged. However, most of the animals are four legged or Quadrupeds or have 2 legs or are Bipedal. This is because having four or two legs ensures that the animal can balance itself. For reference see the link below:
en.wikipedia.org

It is much easier to balance on four legs or two in some cases than three. A three legged deer, for example, wouldn't be able to run as fast and would be eaten by a wolf. I hope this helps.

Because you can't balance as well on three legs

Because if animals have three legs it would be harder to balance and walk for animals.

Balance. We have 4 limbs. Animals have 4 limbs. Their front "legs" are the equivalent of our arms. The bones are named the same, humorous, ulna and radius. Imagine if we walked on all fours ,lost a limb and had to walk on three. It would be harder. We would be disabled. .Not fully able!.  I would quess but stand to be corrected that when an animal loses a limb that it is more disadvantaged at losing a front one ( arm) then a back leg. I quess that makes sense.

Your question is interesting!

According to Darwinism,the animals should have four legs or two so they can run faster and grow better.

If there was they would not be good at any thing

There are know three legged animals for there balance