MathDB

6

Part of 2021 ISI Entrance Examination

Problems(1)

Equilateral Triangle inside Equilateral Triangles.

Source: ISI 2021 P6

7/18/2021
If a given equilateral triangle Δ\Delta of side length aa lies in the union of five equilateral triangles of side length bb, show that there exist four equilateral triangles of side length bb whose union contains Δ\Delta.
Trianglesgeometry