1. ## SAT help

2. Originally Posted by abhilash
Call area of large circle A1, area of medium circle A2, and area of small circle A3.

Do you see why it's A1 - A2 + A3?

3. sketch a y-axis that cuts the large circle vertically thru its center, then take the lower large semicircle and reflect it (flip it) over the y-axis

can you see that the unshaded area = $\pi \cdot 2^2 - \pi \cdot 1^2$ ?