The law of reflection states that if the angle of incidence is 77 degrees the angle of reflection is

77 degrees

Explanation:

According to the Law of Reflection, when a ray of light strikes a surface, the angle of this ray (incident ray) with respect to the normal of the surface is equal to the angle that forms the reflected ray with the same normal of the surface.  

In other words:  

Both the incident ray and the reflected ray and the normal to the surface are in the same plane, in addition, the angle of the incident ray is equal to the angle of the reflected ray.  

In this context, if the angle of incidence is 77 degrees, the angle of reflection is 77 degrees, as well.

d₁ = displacement of tern from arctic to antarctic = 11000 miles

d₂ = displacement of tern from antarctic to arctic =   - 11000 miles

d = total displacement for the journey

total displacement for the journey is given as

d = d₁ + d₂

d = 11000 + (-11000)

d = 0 miles

t₁ = time of travel from arctic to antarctic = 3 months = 3 x 30 days = 90 days

t₂ = time of travel from antarctic to arctic = 3 months = 3 x 30 days = 90 days

t = total time of travel

total time of travel is given as

t = t₁ + t₂

t = 90 + 90

t = 180 days

average velocity is given as

average velocity = total displacement/ total time

v = d/t

v = 0/180

v = 0 miles/day

1 is a answer of a question