Question

how farmet theory explain reflection of light

Answer 1

Fermat theory of least time explains that between any two points light will always take the quickest path and the quickest path between any two points is the straight line.
This formula can prove that angle of incidence is always equal to angle of reflection

Answer 2

hey...
that's Format theory..

The law of reflection states that ,
on reflection from a smooth surface,
the angle of reflected Ray is equal to
the angle of incident Ray.......
The reflected Ray is always in the plan
defined by the incident Ray and normal to the surface.....

thankyou
hope it's help ✌