Tolong dijawab pake cara​

DEG + GEF = 180°

5b + 12 + 2b = 180°

7b + 12 = 180°

7b = 180 – 12 = 168°

b = 168/7

b = 24

DEG = 5b + 12

= 5 (24) + 12

= 120 + 12

= 132°