Question

Plz help ill give you brainlist

Answer 1

In terms of diameter (d), the area (A) of a circle is given by
  A = (π/4)d²
For your larger circle ...
  A = (π/4)*(24 km)²
  A = 144π km² . . . . . . . . area of larger circle

For your smaller circle ...
  A = (π/4)*(8 km)²
  A = 16π km² . . . . . . . . . area of smaller circle


The ratio of the two areas is
  (larger area)/(smaller area) = ((π/4)*(24 km)²) / ((π/4)*(8 km)²)
  = (24/8)² . . . . . . . . . . . . π/4, km cancel, so it simplifies to this
  = 3²
  = 9 . . . . . . this many small circles have the same area as the larger circle

Changing km to ft does not change the ratio of areas.