Answer:
- The neighbor's fencing project that will cost the most is: Neighbor A.
- The neighbor's fencing project that will cost the least is: Neighbor B.
Explanation:
To calculate the amount of fence that Neighbor A has to put up, you need to add the following distances:

Convert yards to feet (Remember that
:

You know that wood fencing is sold in 8 foot sections for $111.50, then, the number of sections for this fence will be:
≈18
Then, the cost for this fencing project will be:
To calculate the amount of fence that Neighbor B has to put up, you need to use the formula for calculate the circumference of a circle:

Where r is the radius.
In this case, the radius is:

Substituting, you get:
≈126 feet
You know that the Chain link fencing costs $9.75 per linear foot, then, the cost for this fencing project will be:
To calculate the amount of fence that Neighbor C has to put up, you need to add the following distances:

Convert from feet to yards (Remember that
:

You know that the vinyl fencing can be purchased for $53.55 per linear yard , then, the cost for this fencing project will be:
Therefore, the neighbor's fencing project that will cost the most is: Neighbor A.
The neighbor's fencing project that will cost the least is: Neighbor B.