Answer:
16.85 cm²
Step-by-step explanation:
Find the area of the small circle then subtract the area of the large circle by the small circle
Area of small circle :
πr², where r = 4cm
π(4²) = 50.27 cm²
67.12 - 50.27 = 16.85 cm²
3.24 + 5.70 + 6.17 = 15.11
20.00 - 15.11 = 5.11
He got 5.11$ of change back.