15 POINTS SO DO THIS NOW

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)

Use set builder notation to represent the following set: { -3, -2, -1, 0}

For the following geometric sequence, find the recursive formula. {-80, 20, -5, } i need : ')