ON THE CIRCLE: Measure of angle B= 1/2(measure of arc BC. Arc divided by 2.
IN THE CIRCLE: Measure of angle AEB=1/2(measure od arc AB+ measure of arc DC). Add 2 arcs and divide by 2.
OUTSIDE THE CIRCLE: Measure of angle A=1/2(measur eof arc BC-measure of arc DE). Subtract the 2 arcs and divide by 2.