Question

In circle F what is the measure of arc CB?

17.5
35
70
60

Answer 1

The inscribed angle theorem says that the angle formed by two intersecting chords of a circle (the angle A between the chords AC and AB in this case) has half the measure of the central angle subtended by the arc containing those chords (arc CB in this case). So

`m\angle BAC=\frac12m\angle BFC\implies m\angle BFC=2\cdot35^\circ=70^\circ`