/// <summary>
/// Help method to decide which
/// shape type a GeometricThing is.
/// Sends object to the object's GetPerimeter().
/// </summary>
/// <param name="thing"></param>
/// <returns>0 if thing is null or not suitable, or perimeter value.</returns>
public float GetPerimeter(GeometricThing thing)
{
if (thing != null)
{
var shape = SetObject(thing);
return(shape.GetPerimeter());
}
return(0);
}
/// <summary>
/// Sets a GeometricThing to a definite shape object.
/// </summary>
/// <param name="thing"></param>
/// <returns>a definite object of the abstract class GeometricThing</returns>
private GeometricThing SetObject(GeometricThing thing)
{
if (thing is Rectangle rectangle)
{
return(rectangle);
}
if (thing is Square square)
{
return(square);
}
if (thing is Triangle triangle)
{
return(triangle);
}
if (thing is Circle circle)
{
return(circle);
}
return(null);
}