Count the number of sides and corners on each of the shapes. Shape A, B and D all have 4 sides and 4 corner. Shape C is a triangle. It has 3 sides and 3 corners, so it is the odd one out.

Crows can recognize geometric patterns, suggesting that humans aren't unique in understanding shape structure.

Mathematicians’ Favorite Shapes Hold the Key to Big Mathematical Mysteries ...

Crows are considered to be among the smartest creatures on Earth. They have cognitive abilities at the levels of five- […] ...

Scientists tested crows on their ability to recognize “geometric regularity,” a skill previously assumed to be unique to ...

Crows are able to look at a handful of four-sided shapes and correctly distinguish those that exhibit ... Previously, ...

A new study shows that like humans, crows can recognize geometric regularity, making them the first nonhuman animal known to have this ability.