In high school I had an argument with a friend after seeing a particular XKCD comic calledÂ Movie Narrative Charts. We were in math class at the time, an introductory calculus course if memory serves. 2,420 more words

## Tags » Planar Graphs

#### Euler-PoincarĂ© characteristic (I): Euler's formula and graph theory

This is the introductory note of a sequence of notes dedicated to Euler-PoincarĂ© characteristic. Here, we deal with Euler’s formula from a graph theoritical viewpoint and exhibit several applications including a proof of Pick’s theorem and the classification of Plato’s solids. 1,157 more words