In geometry what is the purpose of sin and cos?

1. the wheeling bridge in west virginia is about 307 meters long. if you walk with a stride of about meter, about how many steps would it take you to cross this suspension bridge?

() at a farm, animals are fed bales of hay and buckets of gain. each bale of hay is in the shape of a rectangular prism. the base side lengths 2 feet and 3 feet, and the height is 5 feet. each bucket of grain is a cylinder with diameter of 3 feet. the height of the bucket is 5 feet as the height of bale. a. which is larger in area, the rectangular base of the bale or the circular base of the bucket? explain how you know b. which is larger in volume, the bale or the bucket? explain how you know

Find the center and the radius of the circle with the equation: x^2-2x+y^2+4y+1=0?