MathDB

309

Part of 1981 All Soviet Union Mathematical Olympiad

Problems(1)

ASU 309 All Soviet Union MO 1981 3 equilateral with 2 equal vectors

Source:

7/23/2019
Three equilateral triangles ABC,CDE,EHKABC, CDE, EHK (the vertices are mentioned counterclockwise) are lying in the plane so, that the vectors ADā†’\overrightarrow{AD} and DKā†’\overrightarrow{DK} are equal. Prove that the triangle BHDBHD is also equilateral
Equilateralequilateralsgeometryvector