MathDB
Problems
Contests
National and Regional Contests
India Contests
India IOQM
2020-21 IOQM India
12
12
Part of
2020-21 IOQM India
Problems
(1)
IOQM 2021 P12
Source:
1/17/2021
Given a pair of concentric circles, chords
A
B
,
B
C
,
C
D
,
…
AB,BC,CD,\dots
A
B
,
BC
,
C
D
,
…
of the outer circle are drawn such that they all touch the inner circle. If
∠
A
B
C
=
7
5
∘
\angle ABC = 75^{\circ}
∠
A
BC
=
7
5
∘
, how many chords can be drawn before returning to the starting point ? https://i.imgur.com/Cg37vwa.png
geometry