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All-Russian Olympiad Regional Round
2003 All-Russian Olympiad Regional Round
8.7
8.7
Part of
2003 All-Russian Olympiad Regional Round
Problems
(1)
BK = 2DC if <ABC =<KAD =<AKD - All-Russian MO 2003 Regional (R4) 8.7
Source:
9/17/2024
In triangle
A
B
C
ABC
A
BC
, angle
C
C
C
is a right angle. Found on the side
A
C
AC
A
C
point
D
D
D
, and on the segment
B
D
BD
B
D
, point
K
K
K
such that
∠
A
B
C
=
∠
K
A
D
=
∠
A
K
D
\angle ABC = \angle KAD =\angle AKD
∠
A
BC
=
∠
K
A
D
=
∠
A
KD
. Prove that
B
K
=
2
D
C
BK = 2DC
B
K
=
2
D
C
.
geometry
equal segments
equal angles