What is the algorithm to determine the absolute of a number

Create a console project in c#. 1. create an interface "imyinterface.cs" - add a method "string imessage()" 2. create a class named "c1.cs" - add 4 private data members, create property for each data member double loanamnout=0.0; double years=0.0; double interests=0.0; double interestrate=0.0; 3. - add a constructor with parameters to assign values to loanamnout, years, interestrate with values that user entered. 4. - add one method “payinterests()” to return the interests interests = loanamnout * interestrate * years 5. - inheritate "imyinterface", implement the method " imessage()", return string "be ready! ” 6. in program.cs, have users to enter loanamnout, years, interestrate. - call method payinterests() to display total interests. - call imessage() to display "be ready! ”