Explanation:
(a). Radius = WX, WY or WT as they are all points going from the centre of the circle.
(b). Diameter = TX or XT as it goes through the circle points.
(c). Chord = UV or TX as it is two points that originate from the centre of the circle.
(d). The diameter is two times the radius, as the radius (WY = 3) we can find out that the diameter is 3 * 2 so 6.