// Setup rectangle for the rectangle mark's location.
ImGearRectangle igRectangle = new ImGearRectangle(10, 10, 300, 100);
// Setup color for the rectangle.
ImGearRGBQuad igRGBQuadFill = new ImGearRGBQuad(40, 200, 40);
// Setup color for the rectangle border.
ImGearRGBQuad igRGBQuadBorder = new ImGearRGBQuad(0, 0, 0);
// Create rectangle with a solid border of width 10, and 33% opacity.
ImGearARTRectangle igARTRectangle = new ImGearARTRectangle(
igRectangle, igRGBQuadFill, igRGBQuadBorder,
ImGearARTPenStyle.SOLID, 10, (int)(0.33 * 255)
);
// Add the annotation to the ARTPage.
igARTPage.AddMark(igARTRectangle, ImGearARTCoordinatesType.IMAGE_COORD);