MathDB
Problems
Contests
National and Regional Contests
USA Contests
USA - College-Hosted Events
Stanford Mathematics Tournament
2019 Stanford Mathematics Tournament
9
9
Part of
2019 Stanford Mathematics Tournament
Problems
(1)
SMT 2019 Geometry #9
Source:
8/8/2023
Let
A
B
C
D
ABCD
A
BC
D
be a quadrilateral with
∠
A
B
C
=
∠
C
D
A
=
4
5
o
\angle ABC = \angle CDA = 45^o
∠
A
BC
=
∠
C
D
A
=
4
5
o
,
A
B
=
7
AB = 7
A
B
=
7
, and
B
D
=
25
BD = 25
B
D
=
25
. If
A
C
AC
A
C
is perpendicular to
C
D
CD
C
D
, compute the length of
B
C
BC
BC
.
geometry