How do i solve this (see image)

In the image, point a marks the center of the circle. which two lengths must form a ratio of 1 : 2? (options are in the images since thought they were harmful phrases)

If f(x)= 3x+6 which of the following is the inverse of f(x)

Credit card a offers an introductory apr of 3.4% for the first three months and standard apr of 15.7% thereafter,