first, you solve the area of the smaller circle, 3^2 times pi, 9pi. since 120 is 1/3 360, it means it is 1/3 of the cirlce. 9/3=3. 3 is what you have to subtract. next, you know the radius of the big circle is 7 and 7^2 times pi is 49 pi. again, you know 120 is 1/3 360 so it has to be 49/3 pi. 49/3pi - 3pi= 13 1/3 pi.