Answer:
a = 70
b = 60
c = 50
d = 130
Explanation:
Angle a: Angle a is at a vertical angle (makes an x) with the angle above. We know that a straight line is 180 degrees, so the blank angle measure must be 180 - (50+60). This is 70 degrees.
Angle b: Angle b is the corresponding angle measure to 60 degrees, so it is congruent.
Angle c: Angle c is the corresponding angle measure to 50 degrees, so it is congruent.
Angle d: Angle d is corresponding to the supplement of 50 (not 60!!). This means that angle d is 180 - 50, which is 130. You can also check your work by adding the two supplements, c and d, to get 180.