Answer:
B) 63 degrees
Explanation:
All triangles equal up to 180 degrees so you would subtract the lengths you are given by 180.
So 180 - 54 = 126
Now you would divide 126 by 2 since this is an isosceles triangle. Isosceles triangles have two equal sides so 126 divided by 2 equals 63 degrees.
So y = 63 degrees