SOLUTION: Kim and Ken traveled at the same time at the rate of 20 m/min, from the same point on a circular track of radius 600 m. If Kim walks along a circumference and Kim towards the cente

After 10min at 20m/min, they have eached walked 10min*20m/min = 200m.



Let A denote Kim's final position

Let B denote Ken's final position

and C be the center of the circular track



Draw triangle ABC.  



The distance between Kim and Ken is |AB|

|AC| is just a radius, 600m

|BC| is just the radius minus the distance Ken traveled in towards the center:

    600m-200m = 400m 



We know Kim swept out an angle equal to x, where we can set up a proportion of her distance along the circumference with the total circumference:

   or  

    radians



Using the Law of Cosines:







Plug in all the values to get:

 ≈