You would do 4 divided by 3. Which is 1.33 with repeating 3s. You would then round to the nearest hundredth which would 1.33. You can multiply 1.33 and 3 to check your work. Although it might not exactly 4 it is not that big of a deal.
Hope this helps!
ANSWER
Phase shift: 2 units right.
EXPLANATION
The given sine function is
In mathematics, a horizontal shift may also be referred to as the phase shift.
This function is shifted to the right 2 units.
z° = 80° (Being corresponding angles)
y° + 80° = 180° (Being linear pair of angles)
=> y° = 180° - 80°
=> y° = 100°
x° = y° (Being interior opposite angles)
=> x° = 100°