ABC is an isosceles triangle so <B = <C = 40
Sum of interior in a triangle = 180
<A = 180 - <B - <C
<A = 180 - 2(40)
<A = 180 - 80
<A = 100
Given: <A = 2y + 20
Plug in
2y + 20 = 100
2y = 80
y = 40
Answer