Well a full rotation is 360 degrees so what you would do is 1/8 of 360 and to do this you would divide 360 by 8 which is 45 and then you would times by 1 so the answer is 45 degrees. To make this simpler if you have a circle and split it into 4 each segment is 90 degrees and to get an extra 4 you'd divide each segment again by 2 and 90/2 is 45