Help please? Find the values of a, b,c, d,e and f

9514 1404 393

Step-by-step explanation:

The acute angles are all 60°, and the obtuse angles are all the supplement of that, 120°.

Working from the left, we have ...

  a +30 = 60  ⇒  a = 30

  30 +2b = 60  ⇒  b = 15

  5b -5c = 60  ⇒  15 -c = 12  ⇒  c = 3

  10c +d = 60  ⇒  d = 30

  2d +6e = 120  ⇒  60 +6e = 120  ⇒  e = 10

  4f +4e = 120  ⇒  f +10 = 30  ⇒  f = 20

the answer is c

hope this !