clarified and added example (#22450)

* Clarified that not all constructors need to look like that
* Added an example of a class extending a base class and implementing 2 interfaces

guide/english/csharp/class/index.md

@@ -1,11 +1,10 @@
 ---
 title: Class
 ---
+
 ## Class
-
 A class in C# is defined as a reference type. In order to instatiate a variable of a reference type, you must specify the `new` keyword, otherwise the variable will have the default value of `null`. See below for an example.
 
-
 ```csharp
 // The value of variableOne is null at this point.
 NewClass variableOne;
@@ -32,8 +31,8 @@ public class NewClass
 ```
 
 A class is a prototype or blueprint from which objects are created. In C#, the class is defined by using the keyword `class`. A class is used to combine together some methods, properties, fields, events, and delegates into a single unit. A class may contain nested classes too.
-#### Example: Consider the case of Employee Class below:
 
+#### Example: Consider the case of Employee Class below:
 ```csharp
 using System;
 
@@ -73,6 +72,51 @@ namespace CPrograms
 
 A class can inherit from one base class only. However, it can implement from more than one interface.
 
+#### Example of inheriting from one class and 2 interfaces
+```csharp
+// base class: Human
+public class Human {
+    public int Age;
+    
+    public Human (int age) {
+        Age = age;
+    }
+}
+
+// first interface: Student
+public interface Student {
+    int StudentNumber { get; set; }
+}
+
+// second interface: Employee
+public interface Employee {
+    int EmployeeNumber { get; set; }
+    string JobTitle { get; set; } 
+}
+
+// Example of class extending a class and using 2 interfaces
+public class Person : Human, Student, Employee {
+   // new field for Person
+   public string Name;
+   
+   // needed to satisfy Student interface
+   public int StudentNumber { get; set; }
+   
+   // needed to satisfy Employee interface
+   public int EmployeeNumber { get; set; }
+   public string JobTitle { get; set; } 
+
+   // set the instance variables and pass the age to the base class
+   public Person(string name, int age, int studentNum, int employeeNum, string jobTitle) : base(age)
+   {
+       Name = name;
+       StudentNumber = studentNum;
+       EmployeeNumber = employeeNum;
+       JobTitle = jobTitle;
+   }
+}
+```
+
 ## More Information
 Read more about classes [here](https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/class)