Jason designed an arch made of wrought iron for the top of a mall entrance. The 11 segments between the two concentric circles are each 1.25 m long. Find the total length of wrought iron used to make the structure. Round the answer to the nearest meter.
We need to find the perimeter of two half circles, one with a radius of 15/ 2 = 7.5 m, and the other with a radius of [7.5 - 1.25] = 6.25 m
This is given by :
pi [ 7.5 + 6.25] = about 43.2 meters
The rest is easy......the total length of the 11 segments = 11*1.25 = 13.75m
So....the total length of the wrought iron = 43.2 + 13.75 = about 56.95 m