Explanation:
x + 52^o = 90
x = 90 - 52
x = 38^o
k = opposite angle Z
k = 38^o
y + k = 90^o
y + 38^o = 90^o
y = 90^o - 38^o
y = 52^o
y = x = 180^o(sum of angles on straight line)
52 + x = 180^o
x = 180 - 52
x = 128