Question:Find the area between two circles of radii 4 cm and 3 cm . given that the smaller circle lies entirely within the larger.
Answer Area of the bigger circle =`pi(4)^2 cm^2` =16`pi cm^2`.
Area of the smaller circle=`pi(3)^2``cm^2`= 9`pi cm^2` .
Area between the circle = (16`pi`- 9`pi`) `cm^2`= 7`pi cm^2`.
= 7`xx 22/7 cm^2`
= 22 `cm^2`
+ ExplanationNot ModeratedTo find the area between two circles,subtract the area of the smaller circle from that of the larger.
The area between two concentric (i.e.having the same centre) Circles of radii R and r is `pi R^2`- `pi r^2` or `pi(R^2-r^2)`.