Answer:
a) 11%
b) 56%
Step-by-step explanation:
a) A= πr^2   6^2π= 36π   A= 18^2π = 324π
36Ï€/324Ï€ = .111111111111111111111111 or 11%
remember to cancel out the pi symbols when you are showing your work
(put a line across the pi symbols when dividing)
b)  A= πr^2     18^2 π = 324π
   A= Ï€r^2      12^2Ï€ = 144Ï€ Â
       324 – 144  = 180
180Ï€/324Ï€ = .5555555555555555555555556 or 56%
remember to cancel out the pi symbols when you are showing your work
(put a line across the pi symbols when dividing)