MathDB
Problems
Contests
National and Regional Contests
Russia Contests
Novosibirsk Oral Olympiad in Geometry
2020 Novosibirsk Oral Olympiad in Geometry
4
equal angles in square, midpoints (2020 Novosibirsk Oral Geo Oly 9.4)
equal angles in square, midpoints (2020 Novosibirsk Oral Geo Oly 9.4)
Source:
May 24, 2021
equal angles
square
Problem Statement
Points
E
E
E
and
F
F
F
are the midpoints of sides
B
C
BC
BC
and
C
D
CD
C
D
of square
A
B
C
D
ABCD
A
BC
D
, respectively. Lines
A
E
AE
A
E
and
B
F
BF
BF
meet at point
P
P
P
. Prove that
∠
P
D
A
=
∠
A
E
D
\angle PDA = \angle AED
∠
P
D
A
=
∠
A
E
D
.
Back to Problems
View on AoPS