Need regular octagon abcdefgh rotates 360 degree clockwise about it's center . after how many 45 increments will a' ( the image of the a coincide with f

Many newspapers carry a certain puzzle in which the reader must unscramble letters to form words. how many ways can the letters of emdangl be arranged? identify the correct unscrambling, then determine the probability of getting that result by randomly selecting one arrangement of the given letters.