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Durer Math Competition CD 1st Round - geometry
2021.D4
2021.D4
Part of
Durer Math Competition CD 1st Round - geometry
Problems
(1)
AC + OC = AB if <A=30^o, <B=50^o 2020-21 Dürer Round1 D4
Source:
12/1/2022
In the triangle
A
B
C
ABC
A
BC
we have
3
0
o
30^o
3
0
o
at the vertex
A
A
A
, and
5
0
o
50^o
5
0
o
at the vertex
B
B
B
. Let
O
O
O
be the center of inscribed circle. Show that
A
C
+
O
C
=
A
B
AC + OC = AB
A
C
+
OC
=
A
B
.
geometry
incenter
Durer