Can someone help me this ? Finding an angle measure for a triangle with an extended side

Answer:
x° =121°
Step-by-step explanation:
The inside angles of a triangle together must equal 180°. Therefore, 58° + 63° + n° = 180° if n equals the third angle inside the triangle. So,
180°-(58°+63°)=n°
180° - 121° = n°
59° = n°
Since the outside angle x and 59° must also equal 180°,
180° - 59° = x°
121° = x°
You can also find the exterior angle without finding the interior by adding the two other interior angles together.
58°+63°=x°
121°=x°