Answer:
the answer sdhould be the third one
Recall that
Your sums start at 
, so in order to apply these formulas directly, you need to compensate for the missing first two terms:
Colors of light are each bent a different amount because each color has particular wavelength
The answer is C. The square root of 83 is about 9.1. Because a square has four sides, you multiply 9.1 by 4 to get 36.4. The product rounds to the nearest whole number at 36.
