Question

if the incident and reflected sound wave are at angle of 120' with each other the incident angle should be

Answer 1

Let the angle of incidence as well the angle of reflection be x°.
Now,
As, Angle of incidence =Angle of reflection so,

x°+x°+120°=180°(as a plane surface is involved)
2x°+120°=180°
2x°=180°-120°
2x°=60°
x=60÷2
x=30°.

Therefore the angle of incidence as well the angle of reflection are 30° each...