In a △ABC,∠A=x∘,∠B=(3x−2)∘,∠C=y∘ and ∠C−∠B=9∘.Find the three angles.
If sin90∘−(A+B)=cosx=cosy,
find the value of x and y; if y is the angle C of triangle ABC. (In triangle ABC, ∠A+∠B=90∘)