Circumference of the circle A is 24pie and circumference of the circle B is 12 pie . Which the difference between the areas of A and B?

Question

Circumference of the circle A is 24pie  and circumference of the circle B is 12 pie . Which the difference between the areas of A and B?

anonymous · Answer

108pi

anonymous · Answer

$$Circumference_A=(2\pi)r_A=24\pi$$$$Circumference_B=(2\pi)r_B=12\pi$$Work out the radius in each, then use the formula:
$$Area_A=\frac{1}{2}(2\pi)r_A^2$$$$Area_B=\frac{1}{2}(2\pi)r_B^2$$

anonymous · Answer

Using the circumference formulas, we know that the radius of circle A is 12 and the radius of circle B is 6. Therefore, A's area would be 144pi and the area of B would be 36pi. Then, just subtract these values to find the answer.