c.
x = 130° (exterior opposite angles)
y + x = 180° (linear pair of angles)
=> y + 130° = 180°
=> y = 180° - 130°
=> y = 50°
d.
z = 100° (corresponding angles)
a = 100° (corresponding angles)
x + 100° = 180° (linear pair of angles)
=> x = 180° - 100°
=> x = 80°
y = x (interior opposite angles)
=> y = 80°
b = y (corresponding angles)
=> b = 80°
g.
a = 112° (vertically opposite angles)
b = a (interior opposite angles)
=> b = 112°
x = 78° (vertically opposite angles)
x + y = 180° (interior angles on the same side of transversal)
=> 78° + y = 180°
=> y = 180° - 78°
=> y = 102°
h.
f = 120° (vertically opposite angles)
e = 105° (vertically opposite angles)
c = 120° (corresponding angles)
d = 105° (corresponding angles)
a + d = 180° (linear pair of angles)
=> a + 105° = 180°
=> a = 180° - 105°
=> a = 75°
b + c = 180° (linear pair of angles)
=> b + 120° = 180°
=> b = 180° - 120°
=> b = 60°
