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IMO Longlists
1974 IMO Longlists
37
37
Part of
1974 IMO Longlists
Problems
(1)
For what values of theta will the ball strike? [ILL 1974]
Source:
1/2/2011
Let
a
,
b
a, b
a
,
b
, and
c
c
c
denote the three sides of a billiard table in the shape of an equilateral triangle. A ball is placed at the midpoint of side
a
a
a
and then propelled toward side
b
b
b
with direction defined by the angle
θ
\theta
θ
. For what values of
θ
\theta
θ
will the ball strike the sides
b
,
c
,
a
b, c, a
b
,
c
,
a
in that order?
trigonometry