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Sweden Contests
Swedish Mathematical Competition
1998 Swedish Mathematical Competition
4
4
Part of
1998 Swedish Mathematical Competition
Problems
(1)
<B =? , (ABCD)=(a+b)h/2
Source: 1998 Swedish Mathematical Competition p4
4/2/2021
A
B
C
D
ABCD
A
BC
D
is a quadrilateral with
∠
A
=
90
o
\angle A = 90o
∠
A
=
90
o
,
A
D
=
a
AD = a
A
D
=
a
,
B
C
=
b
BC = b
BC
=
b
,
A
B
=
h
AB = h
A
B
=
h
, and area
(
a
+
b
)
h
2
\frac{(a+b)h}{2}
2
(
a
+
b
)
h
. What can we say about
∠
B
\angle B
∠
B
?
geometry
angles
area