This is an English edition of 初等数学复习及研究（平面几何）习题解答 (Elementary Mathematics Review and Research (Plane Geometry): Exercise Solutions) by 尚强 (Shang Qiang), published by Harbin Institute of Technology Press in 2009. It's the companion answer book to a classic Chinese plane geometry textbook, and it's full of good olympiad-style Euclidean geometry problems.
I'm slowly working through it, translating the problems and writing up the solutions. It isn't a word-for-word translation. The original solutions are often one-line hints that only make sense next to the figure and the textbook, so I expand each one into a complete argument, keeping the author's method. Where the original has a mistake, I fix it.
Each exercise set comes as two PDFs: the problems on their own, if you want to try them first, and the problems with solutions. New sets will appear here as they're finished. Problem numbers follow the book, which doesn't give answers for every problem, so some numbers are skipped.
| Section | Topics | PDFs |
|---|---|---|
| Exercise Set 2 | Congruent triangles, inequalities in triangles, midlines, centroid, incenter, circumcenter and orthocenter | Problems · Solutions |
Last updated 29 September 2026