A racetrack is in the form of a ring whose inner circumference is 352 m  and outer circumference is 396 m. Find the width and the area of the track.
Let r and R be the radii of inner circle and outer boundaries respectively.Then,Circumference of inner circle = 2πr=352 r=2π352​ and Circumference of outer circle = 2πR=396 ⇒R=2π396​Width of the track =(R−r)=2π396​−2π352​=2π44​=244​×227​=7Width of the track is 7 m.Again, R+r=2π396​+2π352​=2π748​Area of the track =π(R2−r2)=π(R−r)(R+r)=π×7×2π748​=2618Therefore, the area of the track is 2618 m2.