Geometry - Angle Chasing 3
Geometry
Level
pending
Find the measure of
(in degrees)).
The answer is 55.
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1 solution
The angle which an arc of a circle subtends at the center is double that
which it subtends at any point on the remaining part of the circumference. Therefore,
∠
B
O
C
=
2
×
∠
B
A
C
=
2
(
3
5
)
=
7
0
∘
Since
△
O
B
C
is isoceles with
O
B
=
O
C
,
∠
O
B
C
=
∠
O
C
B
=
2
1
8
0
−
7
0
=
5
5
∘