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National and Regional Contests
Korea Contests
Korea Junior Mathematics Olympiad
2024 Korea Junior Math Olympiad (First Round)
16.
16.
Part of
2024 Korea Junior Math Olympiad (First Round)
Problems
(1)
Geometry
Source: 2024 KJMO first round
10/27/2024
There is an Equilateral trapezoid
A
B
C
D
.
ABCD.
A
BC
D
.
A
B
ˉ
=
60
,
B
C
ˉ
=
D
A
ˉ
=
36
,
C
D
ˉ
=
108.
\bar{AB} =60, \bar{BC}=\bar{DA}= 36, \bar{CD}=108.
A
B
ˉ
=
60
,
BC
ˉ
=
D
A
ˉ
=
36
,
C
D
ˉ
=
108.
M
M
M
is the middle point of
A
B
ˉ
\bar {AB}
A
B
ˉ
, and point
P
P
P
on
A
M
ˉ
\bar{AM}
A
M
ˉ
follows that
A
P
ˉ
\bar {AP}
A
P
ˉ
=10. The foot of perpendicular dropped from
P
P
P
to
B
D
ˉ
\bar {BD}
B
D
ˉ
is
E
E
E
.
A
C
ˉ
∩
B
D
ˉ
\bar{AC} \cap \bar{BD}
A
C
ˉ
∩
B
D
ˉ
is
F
F
F
. Point
X
X
X
is on
A
F
ˉ
\bar {AF}
A
F
ˉ
which follows
M
X
ˉ
=
M
E
ˉ
\bar{MX}=\bar{ME}
MX
ˉ
=
ME
ˉ
Find
A
X
ˉ
×
A
F
ˉ
\bar{AX} \times \bar{AF}
A
X
ˉ
×
A
F
ˉ
geometry
trapezoid