Sun Rays (as observed from Earth) are either Parallel or Diverging.

They appear diverging.  They are explained as parallel.  
Why the Sun's rays that land on Earth are parallel - The further a planet is from the Sun, the smaller the arc of the Sun's rays that intercept the plant. The Earth is so far away from the Sun that for many purposes, all the Sun's rays can be considered to be parallel.
  • Crepuscular Rays
  • Eratosthenes