Answer:
∠B= 102°, ∠Y= 32°
Explanation:
The sum of the angles in a triangle is 180°.
∠A +∠B +∠C= 180° (∠ sum of triangle)
50° +∠B +28°= 180°
∠B +78°= 180°
∠B= 180° -78°
∠B= 102°
∠X= 180° -100° (adj. ∠s on a str. line)
∠X= 80°
∠X +∠Z +∠Y= 180° (∠ sum of traingle)
80° +68° +∠Y= 180°
∠Y +148°= 180°
∠Y= 180° -148°
∠Y= 32°
Alternatively,
∠Z +∠Y= ∠W (ext. ∠ of triangle)
68° +∠Y= 100°
∠Y= 100° -68°
∠Y= 32°