package { public class actionscript_book_GeometricShapes_com_example_programmingas3_geometricshapes_Circle implements actionscript_book_GeometricShapes_com_example_programmingas3_geometricshapes_IGeometricShape { public var diameter:Number; public function actionscript_book_GeometricShapes_com_example_programmingas3_geometricshapes_Circle(diam:Number = 100):void { this.diameter = diam; } public function getArea():Number { // the formula is Pi * radius * radius var radius:Number = diameter / 2; return Math.PI * radius * radius; } public function getCircumference():Number { // the formula is Pi * diameter return Math.PI * diameter; } public function describe():String { var desc:String = "This shape is a actionscript_book_GeometricShapes_com_example_programmingas3_geometricshapes_Circle.\n"; desc += "Its diameter is " + diameter + " pixels.\n"; desc += "Its area is " + getArea() + ".\n";; desc += "Its circumference is " + getCircumference() + ".\n"; return desc; } } }