A fence must be built to enclose a rectangular area of 20,000 m2 . Fencing material costs $2.50 per foot for the two sides facing north and south and...

A fence must be built to enclose a rectangular area of 20,000 m2 . Fencing material costs $2.50 per foot for the two sides facing north and south and $3.20 per foot for the other two sides. Find the dimensions and cost of the least expensive fence