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All-Russian Olympiad
1974 All Soviet Union Mathematical Olympiad
195
195
Part of
1974 All Soviet Union Mathematical Olympiad
Problems
(1)
ASU 195 All Soviet Union MO 1974 right angle inside a square
Source:
7/4/2019
Given a square
A
B
C
D
ABCD
A
BC
D
. Points
P
P
P
and
Q
Q
Q
are in the sides
[
A
B
]
[AB]
[
A
B
]
and
[
B
C
]
[BC]
[
BC
]
respectively.
∣
B
P
∣
=
∣
B
Q
∣
|BP|=|BQ|
∣
BP
∣
=
∣
BQ
∣
. Let
H
H
H
be the foot of the perpendicular from the point
B
B
B
to the segment
[
P
C
]
[PC]
[
PC
]
. Prove that the
∠
D
H
Q
=
9
0
o
\angle DHQ =90^o
∠
DH
Q
=
9
0
o
.
perpendicular
geometry
square