This is an isosceles triangle. Definition of an isosceles triangle Isosceles triangles have at least two sides that are exactly the same length. This forces two of their angles to also be acute angles of exactly [...]
This is an equilateral triangle. What makes a triangle equilateral? Equilateral triangles have all three sides exactly the same length. Because their sides are the same length, the three angles of an equilateral triangle are also [...]
A painting with bilateral symmetry - made using mirroring in a paint program To see what bilateral symmetry is, paint a picture. Take a sheet of paper and fold it [...]
A butterfly has bilateral symmetry. Thanks to Wikimedia Commons What is bilateral symmetry? A shape has bilateral symmetry when it is the same on both sides of a line drawn [...]
The yellow string is one of the arm nerves of a cat By around two billion years ago, some eukaryote cells were able to sense changes in their surroundings and [...]
A flatworm When did flatworms evolve? The first flatworms, or platyhelminthes, probably evolved from something like a hydra about 550 million years ago. What's a hydra? Proterozoic Eon All our [...]
