In circle O. AD and BE are diameters. The measure of arc AB is 55° and the measure of arc CD is 25° B с F D E What is the measure of BC ? 090 O 110 O 100 O 80

Answer:
100°
Step-by-step explanation:
the total of all angles around O on one side of AD is 180° (as that would represent a half-circle).
and the sum of the arc angles AB + BC + CD covers the whole 180°.
so, we have
180 = 55 + BC + 25
180 = 80 + BC
BC = 100°