Answer:
1 . EF is a secant of OX
2. DF is a chord of OX.
3. AABC is made of tangents to OX
4. ∠DEF is an inscribed angle of OX.
Step-by-step explanation:
Secant is line which intersects a circle from two distant points. Locus is a set of points which is same distance from the center of a circle. Chord is a straight line whose end points lie on circular arc of a circle. Tangent is a line which touches the circle at one point only.