How to simplify i^2 with all steps and the answer

Well.. I'm not sure if I remember this correctly but doesn't "i" represent the square root of -1? Therefore if you square a square root, they cancel out and you're left with -1 as your answer. 

Steps would be to:
change "i" to the square root of -1
put the exponent 2 outside of that
cancel the square root and the exponent
answer= -1

Use the Pythagorean Theorem
RP^2 = 5.3^2 + 3^2
RP^2 = 28.09 + 9
RP^2 = 37.09
RP = 6.0901559914
So, the answer is 6.1