When you rotate a rectangle, you might want to find the bounding box that the rotated rectangle is contained in.

The code below will give you the width and height of the bounding box.

/** * Gets the bounding box dimensions of the rectangle rotated by the angle. * @param intAngle The angle in degrees about which the rectangle is being rotated, clockwise. * @param intWidth The width of the rectangle. * @param intHeight The height of the rectangle. * @return */ function getBoundingBox( $intAngle, $intWidth, $intHeight ) { $fltRadians = deg2rad( $intAngle ); $intWidthRotated = $intHeight * abs( sin( $fltRadians) ) + $intWidth * abs( cos( $fltRadians ) ); $intHeightRotated = $intHeight * abs( cos( $fltRadians ) ) + $intWidth * abs( sin( $fltRadians ) ); return array( $intWidthRotated, $intHeightRotated ); }