$7$: Polymorphic Shapes Create a base class $`$Shape$`$ with virtual methods to calculate area and perimeter. Derive classes like $`$Rectangle$`,`$Circle

Dempsey, Nicholas. C# & C$++$: $5$ in $1$: From Zero to High$-$Paying Jobs: The Updated Crash Course Guide with Secret Hacks to Learn C# & C$++$ in Just One Week $+50$ Hands$-$On Exercises $($p$.136).$ Kindle Edition.