MathDB
Extending edges of triangle increases area by a factor of 13

Source: Germany 2023, Problem 2

June 16, 2023
geometrygeometry proposedarea of a triangleareasareageometric inequality

Problem Statement

In a triangle, the edges are extended past both vertices by the length of the edge opposite to the respective vertex. Show that the area of the resulting hexagon is at least 1313 times the area of the original triangle.