Use the above figure to answer the question. what's the angle between the tangents at t in the figure?

Can someone me with these two circle theorem questions asap?

Aword processing program requires a 7- digit registration code made up of the digits 1,2,4,5,6,7 and 9 each number has to be used and no number can be used mor than once how many codes are possible

Which shows the first equation written in slope-intercept form? 1/2 (2y + 10) = 7x