Answer:
A.
Step-by-step explanation:
The sum of interior angles in a triangle is 180°
2y + 54 = 180
2y = 126
y = 63
A.)63°
54°+63°+63°=180°
For this, you would use the Angle Sum Theorem which means the sum of the measures of a triangle's angles should always end up equaling 180°
A P E X Hope this helps Happy Holidays
