R – Function executing as constructor, but not as function

I've the following code in my displayandmove.as file:

package {

    import flash.display.MovieClip;

    public class FigureConstruct extends MovieClip {

        public function displayandmove() {
            this.height = stage.stageHeight/5;
            this.width = stage.stageWidth/5;
        }

    }

}

And I have the following on frame 1 of my displayandmove.fla:

var figure:FigureConstruct = new FigureConstruct();
stage.addChild(figure);
figure.x = stage.stageWidth/2;
figure.y = stage.stageHeight/2;

These files are in the same directory. In my FLA library I have my figure MovieClip and it ha a Class of "FigureConstruct" and base class of "flash.display.MovieClip".

Currently the code above works fine because I figured out that if I execute the object size code as a construct — using the file name as the function name — it works.

What I originally intended to do was to have my function named "sizeFigure()" in my AS file and then call "figure.sizeFigure();" after "stage.addChild(figure);" on frame 1 of my FLA.

This output

Error #1006: value is not a function.

Can anyone explain what I am missing to get this to execute as a function rather than as a constructor?

I thought maybe I am goofing up when I set my Class and Base Class pointers for the library object… but not sure.

PS – Sorry if I am misusing terms, still nailing those down as I go.

Edit: Below is the original code that does not seem to work until after I changed the name of my function to the name of the file, making it the class constructor. The above version works, below does not.

displayandmove.as

package {

    import flash.display.MovieClip;

    public class FigureConstruct extends MovieClip {

        public function sizeFigure() {
            this.height = stage.stageHeight/5;
            this.width = stage.stageWidth/5;
        }

    }

}

displayandmove.fla:

var figure:FigureConstruct = new FigureConstruct();
stage.addChild(figure);
figure.sizeFigure();
figure.x = stage.stageWidth/2;
figure.y = stage.stageHeight/2;