On a baseball field, the infield are created by the baselines is a square. In a youth baseball league for 9- to 12-year-olds, this area is 3600ft2. The distance between each base in a league foe 4-year-olds is 20 ft less than it is for 9- to 12-year-olds. What is the distance between each base for 4-year-olds?