If sin θ = 0.57 then sin (π-θ)=?

In trigonometry laws, there's a equation to solve this problem : 
sin (a-b) = sin(a) . cos(b) - sin (b) . cos(a),

so by assuming that a = π, b = θ, so the equation will be like this..
sin (π-θ) = sin(π) . cos(θ) - sin (θ) . cos(π), 
             = 0 . cos(θ) - sin(θ) . (-1) 
             = sin(θ) = 0.57

Hope this will help you :)