Answer:
Chord: RT (and RS and TU, but those are also diameters)
Diameter: RS or TU
Radii: OU, OS, OT, or OR
Step-by-step explanation:
Chord: A line segment joining two points on a curve. Doesn't have to cross the center. (AKA, they have to touch the outer edge of the circle.)
Diameter: Chord that crosses the center of the circle(All examples given above cross center O)
Radius: Line segment that goes from the center of a circle to an endpoint that lies on the circle.
