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Mathematics
Mathematics
Problem
In one or two sentences, explain why
sin
(
90
∘
−
θ
)
\sin(90^\circ - \theta)
sin
(
9
0
∘
−
θ
)
equals
cos
θ
\cos \theta
cos
θ
for any acute angle
θ
\theta
θ
in a right-angled triangle.
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