Please, first share whatever you know (or think) about how to solve this problem. In the end you want to be able to solve such problems independently.
I'll give you some hints:
1). In Problem (a), <ABD and <CBD add up to 180 degrees; together they constitute a "straight angle:" (the larger angle) + (the smaller angle) = 180 deg. This boils down to a question in algebra: one angle is 6.2 times greater than the other. How do you represent this algebraically?