First part. By definition, a straight line tangent to a circle is one that touches the circle at exactly one point, without ever entering its interior.
In this case, a tangent line to the circle is the line KG, because intersects the circle only in D.
Second part. By definition, a straight line secant to a circumference is one that touches the circumference at two points.
In this case, a secant line to the circle is the line EJ because intersects the circle at I and F.
Third part. By definition, the chord of a circle is a segment that joins two points on the circumference without having to go through the center.
In this case, a chord of the circle is the segment ID.