Step-by-step explanation:

If we draw a parallelogram so that the top left point is A, the top right is B the bottom right is c and the bottom left is D and do WXYZ in the same order with the larger parallelogram with the same shape, then WZ would be proportional to AD.
2,150 estimated would be 2,000. Since she flies there and back multiply 2,000 by 2. Since she flies it twice multiply 4,000 by 2. Estimated: 8,000 miles. To find the exact miles Do the same thing but with 2,150: 2,150 times 2 = 4,300. 4,300 times 2 = 8,600. She flies exactly 8,600 miles per year :)