13 and 15 can someone please help me understand this

Ineed with number 6 , explain how to get 1978

1) in triangle the, what is the measure of angle t (in degrees)? 2) in triangle bat, the measure of angle b is 66∘, and the measure of angle t is 77∘.what is the measure of the exterior angle at a (in degrees)?

Laura read 1/8 of a comic book in 2 days. she reads the same number of pages every day. what part of the book does she read in a week