Question

What is the value of y?

Answer 1

180 = y + y + 30 + 40
180 = 2y + 70
180 - 70 = 2y
110 = 2y
y = 110/2
y = 55

Answer 2

the sum of triangle is 180:

`y + 40 + y + 30 = 180 \\ 2y + 70 = 180 \\ 2y = 180 - 70 \\ 2y = 110 \\ y = (110)/(2) \\ y = 55`