My professor at college loves geometry and discrete mathematics.
He gave us a question let see if you can solve it.
He asked us
how many unique squares which have the same size and each corner colored in red,green and blue?
Two squares will be called Unique to each other if no matter how you rotate them or flip them they will not look the same.
Here is an example of two equilateral triangle that aren't unique to each other.
(same concept but with triangles didn't want to give spoilers in the example)
The reason why they not unique because You can flip one of them (in y axis) and you will get the same triangle.