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Moscow Mathematical Olympiad
1952 Moscow Mathematical Olympiad
215
215
Part of
1952 Moscow Mathematical Olympiad
Problems
(1)
MMO 215 Moscow MO 1952 inequality with inradii
Source:
8/8/2019
△
A
B
C
\vartriangle ABC
△
A
BC
is divided by a straight line
B
D
BD
B
D
into two triangles. Prove that the sum of the radii of circles inscribed in triangles
A
B
D
ABD
A
B
D
and
D
B
C
DBC
D
BC
is greater than the radius of the circle inscribed in
△
A
B
C
\vartriangle ABC
△
A
BC
.
geometry
incircle
inradius
geometric inequality