sinθ≡2sin(θ/2)cos(θ/2).
sin(θ/2)=16/34=8/17; cos(θ/2)240/289=√(1-64/289)=15/17.
sinθ=2(8/17)(15/17)=240/289.
Sine=opposite/hypotenuse, so adjacent2=hypotenuse2-opposite2=
2892-2402=(289-240)(289+240)=(49)(529).
adjacent=7×23=161.
tanθ=opposite/adjacent=240/161.