need help understanding

For an arc length s, area of sector A, and central angle O of a circle of radius r, find the indicated quantity for the given value. A -61.2mi ,r-61.2 mi, 0 2 0 0000000126 radian (Do not round until the final answer. Then round to three decimal places as needed ) Solve | tan x] = 1/3 in [0,2x). The solution(s) in [0,2x) is/are (Use a comma to separate answers as needed. Type an exact answer, using x as needed.)