(1) On the draft paper, first talk about the angle AOB, draw BOC with OB as the base, and then talk about OD and OE. It is known that OD bisects the angle AOB, so the angle BOE is 30 degrees. OE bisects the angle BOC, and the angle BOD is 20 degrees. So find the degree of DOE = angle BOC- angle BOD= 10 degree.

(2) On the draft paper, first talk about the angle AOB, then draw BOC with OB as the base, and then talk about OD and OE, so we know that OD bisects the angle AOB, so the angle BOE is 30 degrees. OE bisects the angle BOC, and the angle BOD is 20 degrees. So find the degree of DOE = angle BOC+ angle BOD=50 degrees.

To adopt, O(∩_∩)O~