HELPPP I need help finding the volume for each one, and I don’t really know how, and if you want me to help can you pls explain how you got it because I have more of these.

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)

What is the length of the missing leg in this right triangle? 18 mm 24 mm 26 mm 32 mm

Identify the converse of the following conditional: if a point is in the first quadrant, then its coordinates are positive. if the coordinates of a point are not positive, then the point is not in the first quadrant. if the coordinates of a point are positive, then the point is in the first quadrant. if a point is in the first quadrant, then its coordinates are positive. if a point is not in the first quadrant, then the coordinates of the point are not positive.