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Looking back to move forward

Euclidean Geometry

The Origin of the Infamous Law of Cosines

When algebra meets…

Euclidean Geometry

2011 Indonesia Regional Olympiad Problem 4

Geometry Challenge #12

Euclidean Geometry

How to Prove the Law of Sines: a Complete Guide

When algebra meets…

Euclidean Geometry

2017 Canada National Olympiad Problem 4

Geometry Challenge #11

Euclidean Geometry

2011 Austria National Olympiad (Part 2) Problem 6

Euclidean Geometry

2015 India Regional Olympiad Problem 1

Geometry Challenge #9

Given two circles Γ and Σ with centers O and P, respectively, such that P lies on Γ. Let A be a point on Σ, and M be the midpoint of AP. If B is…

Euclidean Geometry

2010 Indonesia National Olympiad Problem 2

Geometry Challenge #8