Question

In an angle between an incident ray and reflected sound is at 90degree what will be the angle of incidence and why?

Answer 1

the angle of incidence is 45 degrees because the angle between incident and normal and reflected and normal is same

so that angle of incidence + angle of reflection = 90 degrees

Answer 2

let angle of incidence=i
let angle of reflection=r

acc. to the question,
i+r=90°
and by reflection law states that i=r,
so, i=r=45°

hope it helps