In the figure below what is the Angular error of closure ? If the true total lenghth of the perimeter is 573.468\', what is the Linear error of closure, Relative Accuracy and Order/Class? Solution sum of internal angle of a polygen is (n-2)180 in this case n= no of side = 5 sum of total internal angle = (5-2)*180 = 540° here sum of all angle is 109°46\'30\" + 8057\'00\"+ 115°45\'00\" + 90° +143°56\'30\" = 540°25\'00\" angular erroe = 540°25\'00\" - 540° = 0°25\'00\" (+ve) perimeter= sum of all sides= linear error = final length - orginal lingth I can\'t understand what this symble indicates 179\' 4-1/4\" ( in bold one ) .