Answer:
arc YZ = 59°
Explanation:
Since XZ is a diameter then ∠ XAZ = 180°
∠XAY + ∠ YAZ = ∠ XAZ , substitute values
11w + 5w + 4 = 180, that is
16w + 4 = 180 ( subtract 4 from 180 )
16w = 176 ( divide both sides by 16 )
w = 11
Thus ∠ YAZ = 5w + 4 = 5(11) + 4 = 55 + 4 = 59°
The arc YZ is the measure of the central angle it subtends, thus
arc YZ = 59°