(a) Let An be the area of a polygon with n equal sides inscribed in a circle with radius r. By dividing the polygon into n congruent triangles with central angle 211", show that 1 2 _ 211 An = Em" 3171(7) (b) Show that limAn = m2. [Hint: Use the fact lim Si\" = 1.] n>oo x>0 x