The equivalent ratios are A and D.
Here's an explanation:
When you look at D, you see that 12 is a multiple of 6, and 16 is a multiple of 8. So you know that it looks like they're equivalent. Then you test it out, 12/2=6. 16/2=8. so 12:16 = 6:8. Eyeballing it first can save time sometimes.
You are looking for the perimeter of the pool. The perimeter of rectangles can be measured by using the formula 2W + 2L = P (2 * width + 2 * length = perimeter). Using the formula, 2(40) + 2(20) = P, 80 + 40 = P, P = 120. The answer is C. 120 yards.
