Create new console project, and create base class like this:

public class BaseClass
{
	public BaseClass(int value)
	{
		Console.WriteLine("BaseClass constructor with value: " + value.ToString());
	}
}


Now, let's derive class from our BaseClass:

class DerivedClass: BaseClass
{
	public DerivedClass(int value)
	: base(value)
	{
		Console.WriteLine("DerivedClass constructor with value: " + value.ToString());
	}
}


If we create our Main method like this:

class Program
{
	static void Main(string[] args)
	{
		BaseClass a = new BaseClass(10);
		DerivedClass b = new DerivedClass(20);
		Console.ReadKey();
	}
}


Result will be like this:

BaseClass constructor with value: 10
BaseClass constructor with value: 20
DerivedClass constructor with value: 20

Example project you can download from here.