Question

How I can know b, c, and d?

Answer 1

b=120

c=60

d=60

Explanation:

here,a=120 (given)

1) a=b (vertically opposite angles are equal)

so, b=120

2) b+c=180 (sum of angles in straight line is 180)

120+c=180

c=180-120

so, c=60

3) c=d (vertically opposite angles are equal)

so, d=60

Answer 2

b=120

c=60

d=60

Explanation:

Vertical angles are congruent . 180-120= 60. Sorry the explanation isn't that good.