Answer:
Correct option: first one -> 45°
Step-by-step explanation:
FC is a diameter, so the arc FBC measures 180°.
If we have that FBC = FB + BC, then we can find the value of BC:
FB + BC = 180
135 + BC = 180
BC = 45°
If we call the center of the circle 'O, we have that the central angle EOF and the central angle BOC are vertically opposite angles, so EOF = BOC.
The central angles have the same measure that the arcs they are related, so we have that:
angle BOC = arc BC = 45°
angle BOC = angle EOF
angle EOF = arc EF = 45°
Correct option: first one
