Explanation:
y = 123° (vertically opposite angle)
x = 123° (Alternate Exterior angle)
z = 123 + z = 180 ( as all sum of all angles on a sprint line is 180°)
→ z = 180 - 123 = 57°
→ z = 57°
therefore,
y = 123°
x = 123°
z = 57°
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btw great handwriting! (◔‿◔)