Consider two circles
C1:x2+y2=25 and
C2:(x− α)2+y2=16, where
α∈(5,9). Let the angle between the two radii (one to each circle) drawn from one of the intersection points of
C1 and
C2 be
sin−1(). If the length of common chord of
C1 and
C2 is
β, then the value of
(αβ)2 equals ____