## Elementary Geometry for College Students (6th Edition)

Given in a regular polygon,each central angle measures 30$^{\circ}$ Each side of the polygon =5.7 in We need to find the perimeter of the polygon We know the relationship between the central angle and number of sides Central angle = $\frac{360 ^{\circ} }{n}$ 30 $^{\circ}$ = $\frac{360 ^{\circ} }{n}$ n = $\frac{360}{30}$ = 12 Therefore the polygon consist of 12 sides The perimeter of polygon = np = 12*5.7 = 68.4 in