In the figure below, O is the common centre of the two

In the figure below, O is the common centre of the two circles. The area of the shaded part A is twice that of the shaded part B. i. What fraction of the figure is shaded? (3 Marks) ii. If the difference in area between the two circles is 112 cm^2, what is the area of the bigger circle? (7 Marks) A B 45 O