Please try to answer with clear step by step by step instruction and label each variable so that I am able to understand it easily. Thanks!

As a property owner, you want to fence a garden which is adjacent to a road. The fencing next to the road must be stronger and cost $6 per foot. The fencing on the other sides cost $4 per foot. The area of garden is 2400 square feet.

1. Draw several diagrams to express the situation and calculate the cost for each configuration, and then estimate the dimension of minimum cost.
2. Find the function that represents the cost in terms of one of its sides.
3. Using the graphing utility, graph this cost function
4. Find the dimension that minimizes the cost of fencing and compare this with your estimate based the diagram you made.