This triangle is inscribed with contrast enhancing colors making it easier to use. Using two 45Ã‚Â° triangles provides an easy method of plotting and performing chart work. With its protractor scales, the triangle is easily aligned in any direction with a chart meridian. Direction is maintained as one triangle is slid along the other to the desired position. Durable, clear vinylite. Short sides 7-1/2″, .08″ thick, (one per pack).