MathDB
new triangle has area 1/7 of original equilateral

Source: Eotvos 1942 p3

September 10, 2024
geometryareasEquilateral

Problem Statement

Let AA', BB' and CC' be points on the sides BCBC, CACA and ABAB, respectively, of an equilateral triangle ABCABC. If AC=2CBAC' = 2C'B, BA=2ACBA' = 2A'C and CB=2BACB' = 2B'A, prove that the lines AAAA', BBBB' and CCCC' enclose a triangle whose area is 1/71/7 that of ABCABC.