Friends. The walls are not orthogonal…

“When will I use Euclidean construction in real life?”
“When you want to make a shelf go around a corner, of course”.

There exists a bin. A rubbish proof.

There are 2^4=16 ways to set the lights in my parents’ kitchen but on average how many ‘flicks’ does it take me to get the combination I want?

Which is the odd one out?

Correct solution to follow.