Respuesta :

The relationship of arcs is:
 S '/ S = ((1/9) * pi * r) / (2 * pi * r)
 Rewriting we have:
 S '/ S = ((1/9)) / (2)
 S '/ S = 1/18
 Therefore, the area of the shaded region is:
 A '= (S' / S) * A
 Where A: area of the complete circle:
 Clearing we have:
 A = (A ') / (S' / S)
 Substituting:
 A = ((1/2) pi) / (1/18)
 A = ((18/2) pi)
 A = (9pi)
 Answer:
 The area of the circle is:
 
A = (9pi)