This is the homepage of Evan Chen
(known also as vEnhance on certain websites).
I am a math PhD student at MIT,
starting in September 2018.
My CV is here.
Here is a list of my major coursework
from undergraduate and graduate school.
Most of my research is either in number theory
or enumerative/algebraic combinatorics.
My papers are linked on my publications page,
and also on the arXiv.
I am actively involved with math olympiad competitions
and have authored several olympiad materials,
most notably including a geometry textbook.
I also teach my own classes.
I am on GitHub,
You can also see my personal page for trivia about myself.
The nine-point circle of $\triangle BIC$ is orthogonal to
the circle with diameter $ST$.
Problem source: [Taiwan TST Quiz 2015](https://artofproblemsolving.com/community/c6h1113644p5087419)