$89,999 rounded to the nearest 10,000

Turner's mom measured his room to see how long the wallpaper border needed to be. if two walls are 15 feet long and two walls are 12 feet long, how long should the strip of border be cut?

Both the red and blue line segments stretch from the center of the circle to a point on the circle. the length of the blue segment is 5. how long is the red line segment?

Describe the 2 algebraic methods you can use to find the zeros of the function f(t)=-16t^2+400.