2020 USOMO Problems
Day 1
Problem 1
Let
be a fixed acute triangle inscribed in a circle
with center
. A variable point
is chosen on minor arc
of
, and segments
and
meet at
. Denote by
and
the circumcenters of triangles
and
, respectively. Determine all points
for which the area of triangle
is minimized.
Problem 2
An empty
cube is given, and a
grid of square unit cells is drawn on each of its six faces. A beam is a
rectangular prism. Several beams are placed inside the cube subject to the following conditions: