Point S has coordinates (2,6). If you rotate S 90° about the origin, (0,0), what are the coordinates of S'?

Geometry answer picture question pls . reason and statements

Acircular city park has a sidewalk directly through the middle that is 111 - feet long. if each bag of fertilizer covers 50 square feet, then determine how many bags of fertilizers the parks and recreation department needs to use to cover the circular park. ignore all the sidewalks around and through the park.

Can someone me out here and the tell me the greatest common factor