423.52 m should be the right one First The rectangle part with the length is 105m, so you add 105 with 105 that make 210. For the semicircle part, we need to find the circumference of the circle C = 2*pi*r ==> semi Circle circumference = 1/2(2*pi*r) = pi*r 68 is diameter ==> radius should be 34, and the Circumference of 1 semicircle should be 34*pi. We have 2 semicircles, so 2 have 68*pi In the end Total perimeter = 210 + 68*pi = 423.52
