1
a and d are supplementary angles, forming a line or adding to 180 degrees, so
d =180 - 120 = 60 degrees
2
f and h are called vertical angles, which are congruent.
h=70 degrees
3
c and f are supplementary. I think they're called consecutive angles.
f = 180 - c = 70 degrees
4
b and c are supplementary, c and g are congruent so
g = 180 - b = 120 degrees