PI (Math.PI property)

A mathematical constant for the ratio of the circumference of a circle to its diameter, expressed as pi, with a value of 3.141592653589793.

Availability: ActionScript 1.0; Flash Lite 2.0 - In Flash Player 4, the methods and properties of the Math class are emulated using approximations and might not be as accurate as the non-emulated math functions that Flash Player 5 supports.

Example

The following example draws a circle using the mathematical constant pi and the Drawing API.

drawCircle(this, 100, 100, 50);
//
function drawCircle(mc:MovieClip, x:Number, y:Number, r:Number):Void {
    mc.lineStyle(2, 0xFF0000, 100);
    mc.moveTo(x+r, y);
    mc.curveTo(r+x, Math.tan(Math.PI/8)*r+y, Math.sin(Math.PI/4)*r+x, Math.sin(Math.PI/4)*r+y);
    mc.curveTo(Math.tan(Math.PI/8)*r+x, r+y, x, r+y);
    mc.curveTo(-Math.tan(Math.PI/8)*r+x, r+y, -Math.sin(Math.PI/4)*r+x, Math.sin(Math.PI/4)*r+y);
    mc.curveTo(-r+x, Math.tan(Math.PI/8)*r+y, -r+x, y);
    mc.curveTo(-r+x, -Math.tan(Math.PI/8)*r+y, -Math.sin(Math.PI/4)*r+x, -Math.sin(Math.PI/4)*r+y);
    mc.curveTo(-Math.tan(Math.PI/8)*r+x, -r+y, x, -r+y);
    mc.curveTo(Math.tan(Math.PI/8)*r+x, -r+y, Math.sin(Math.PI/4)*r+x, -Math.sin(Math.PI/4)*r+y);
    mc.curveTo(r+x, -Math.tan(Math.PI/8)*r+y, r+x, y);
}