1. This is a rule which helps a person identify if a number is divisible by nine. There is no specific answer to why this is observed but I believe that is just how multiples of nine and three behave!
It is the same with the multiples of three as well!
By the way the 6 digit number could be 513315 thanks, hope that helps!!
Use Pythagorean theorem to solve. a^2 + b^2 = c^2 6^2 + b ^2 = 14^2 36 + b^2 = 196 Subtract 36 from both sides. b^2 = 196-36 b^2 = 160 Take the square root of both sides. b = sqrt 160 As a decimal b = 12.649 As a simplified radical b = 4sqrt10