Keying shapes

  1. stippled

  2. circle

  3. right angles

  4. 3 sides

The key for the triangle (C) is 1, 4, yes.

Note than angles is no longer used as a shared trait; the fact that both A and C have angles is ignored.

For example, humans and bees both have 2 eyes, but those are not used to establish relationships between humans and bees.

Copyleft Peter Chen