Given, ∠X=62∘,∠XYZ=54∘
YO and ZO are the bisectors of ∠XYZ and ∠XZY respectively.
According to the question
∠X+∠XYZ+∠XZY=180∘ (Sum of the interior angles of the triangle.)
⇒62∘+54∘+∠XZY=180∘
116∘+∠XZY=180∘
∠XZY=64∘
Now, ∠OZY=12∠XZY(ZO is the bisector.)
⇒∠OZY=32∘
Also ∠OYZ=12∠XYZ (YO is the bisector.)
⇒∠OYZ=27°
Now, ∠OZY+∠OYZ+∠O=180∘ (Sum of the interior angles of the triangle.)
⇒32∘+27∘+∠YOZ=180∘
⇒59∘+∠YOZ=180∘
⇒∠YOZ=121∘