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1984 USAMO
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3
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1984 USAMO
Problems
(1)
USAMO 1984 Problem 3 - Optimize <APC+<BPD
Source: USAMO 1984 Problem 3
8/16/2011
P
,
A
,
B
,
C
,
P, A, B, C,
P
,
A
,
B
,
C
,
and
D
D
D
are five distinct points in space such that
∠
A
P
B
=
∠
B
P
C
=
∠
C
P
D
=
∠
D
P
A
=
θ
\angle APB = \angle BPC = \angle CPD = \angle DPA = \theta
∠
A
PB
=
∠
BPC
=
∠
CP
D
=
∠
D
P
A
=
θ
, where
θ
\theta
θ
is a given acute angle. Determine the greatest and least values of
∠
A
P
C
+
∠
B
P
D
\angle APC + \angle BPD
∠
A
PC
+
∠
BP
D
.
AMC
USA(J)MO
USAMO
geometry unsolved
geometry