Three-dimensional goat

Can we watch the goat from all three different sides without walking around it? As you can see on the photo - yes! But the goat has to be placed in a glass cage. The same with the bear: first he covers his ear and than he uncovers it.

The light beam choose a strange path; they take a shortcut. Instead of taking the straight path to our eye, they first go at an angle, take a straight path to the wall of the cage, they refract on the glass wall and then they go along another straight path to our eye. Instead of choosing one line, they choose a chained path.

It turns out that in reality this route is shorter, but not on paper, but in time. We call it Fermat's principle and it is the basis for the refraction of light (so called Snelius's Law).