Problem
GEO-B1-M08-P005 One Angle on a Chord
#5
★★★☆☆ Level 3 of 5
Points \(A,B,C,D\) lie on one circle, and \(B\) and \(D\) lie on the same side of chord \(AC\). If \(\angle ABC=39^\circ\), find \(\angle ADC\).
Both angles stand on chord \(AC\).
Angles \(\angle ABC\) and \(\angle ADC\) are inscribed and stand on the same chord \(AC\). With the given position, they are equal. Therefore \(\angle ADC=39^\circ\).
The main circle pattern in a mixed context.