What is the rise between the points (0,0) and (8, 12)?

Can someone me and do the problem plz so i can understand it more better

Iwill give ! if m∠a=59 and m∠3=81°, what is m∠b? m∠b= _[blank]_°

Solve: 25 points find the fifth term of an increasing geometric progression if the first term is equal to 7−3 √5 and each term (starting with the second) is equal to the difference of the term following it and the term preceding it.