diameter of the bigger semi-circle is 15 m
circumference of the bigger semi-circle = πd = 15π
diameter of the smaller semi-circle = 15 - 2(1.25) = 15 - 2.5 = 12.5 m
circumference of the smaller semi-circle = πd = 12.5π m
Total length of the segments between the two circles = 11(1.25) = 13.75 m
Total length of wrought iron used = 15π + 12.5π + 13.75 = 100 m
Hope this helps!
