MathDB

5

Part of 1978 Romania Team Selection Test

Problems(2)

1978 geometry.

Source: Romanian TST 1978, Day 1, P5

9/28/2018
Prove that there is no square with its four vertices on four concentric circles whose radii form an arithmetic progression.
geometryArithmetic Progression
A locus contained in an equilateral triangle

Source: Romanian TST 1978, Day 3, P5

9/30/2018
Find locus of points M M inside an equilateral triangle ABC ABC such that ∠MBC+∠MCA+∠MAB=π/2. \angle MBC+\angle MCA +\angle MAB={\pi}/{2}.
geometryPure geometryLocus