Central Angle: An angle whose vertex is the center of a circle. The measure of a central angle is equal to the measure of its intercepted arc. ... Inscribed Angle: An angle whose vertex is a point on a circle and whose sides contain chords.
All you need to do is find (f+g)x = (12x) + (10(1.2)X) which = 24x then in the multiple choice, see which one equals 24x, in this case its C. 5*1.2=6, 6x+6x = 12x*2 = 24x
