信言不美，美言不信。

This is the homepage of Evan Chen (陳誼廷), known also as vEnhance on many websites. I’m an MIT grad student under Wei Zhang, and also a math olympiad coach, volunteer, and YouTuber on the side.

My CV is here. Here is a list of my major coursework from undergraduate and graduate school. These days, I’m interested in number theory and combinatorics. My papers are linked on my publications page, and also on the arXiv.

I am on GitHub, Instagram, Twitch, and WordPress. You can also see my personal page for trivia about myself. Fellow Linux geeks can download my GPG key from keyserver.ubuntu.com or keys.opengpg.org.

If you are a high school student interested in math olympiads, you may visit the beginner’s page, my collection of handouts, or my archive of past problems and solutions.

The nine-point circle of $\triangle BIC$ is orthogonal to the circle with diameter $ST$.
Problem source: Taiwan TST Quiz 2015

About Evan#

Evan is a math PhD student at MIT and one of the United States math olympiad coaches. In addition to serving as the team selection coordinator for the United States, Evan runs his own training program while streaming olympiad math for public entertainment.

As a high school student, Evan was an IMO gold medalist and a winner of the 2014 USA math olympiad, which he took from 12:30am to 5am in Taiwan. He also wrote the popular textbook Euclidean Geometry in Math Olympiads while in high school, which was published in 2016.

Outside of math and teaching, Evan’s hobbies include Korean pop dance, Arch Linux, Hanabi and puzzle hunts.