You can put this solution on YOUR website! What is sin(x) if the sides of an isosceles triangle (not right) are sin(x), cos(x), tan(x)?
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sin(x) = cos(x) if x = pi/4
--> sin(x) = sqrt(2)/2
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Or cos(x) = tan(x)
--> sin(x) = (sqrt(5) - 1)/2