public static Size GetRotatedSize(Size size, double angleToRotate) { var width = Calculator.AbsoluteCos(angleToRotate) * size.Width + Calculator.AbsoluteSin(angleToRotate) * size.Height; var height = Calculator.AbsoluteSin(angleToRotate) * size.Width + Calculator.AbsoluteCos(angleToRotate) * size.Height; return(new Size(width, height)); }