Answer:
AB - secant
DB - diameter
AB - chord
OB - radius
BC - tangent
(In the order they are in the picture)
Step-by-step explanation:
AB - The line goes through the circle and does not go through the center. This fits the definition of a secant, so line AB is a secant.
DB - Segment DB goes through the center and has endpoints on the circle. This fits the definition of a diameter, so DB is a diameter.
AB - Segment AB has endpoints on the circle and does not go through the center. This fits the definition of a chord, so segment AB is a chord.
OB - Segment OB is basically from the center to a point on the circle. This fits the definition of a radius, so segment OB is a radius.
BC - Line BC intersects the circle in only one point and does not go through it. This fits the definition of a tangent, so line BC is a tangent.
