The area ratio of the two circles AB is 4:25, the radius difference is 6cm, and the area of circle a is () square centimeter?

The area ratio of the two circles AB is 4:25, the radius difference is 6cm, and the area of circle a is () square centimeter?

The area ratio is 4:25
So the radius ratio is 2:5
So the radius of a is 6 (5-2) × 2 = 4cm
So the area of a is 3.14 × 4 × 4 = 50.24 square centimeter