tolong jawab soal PENGAYAAN 1-5 ini berserta jalan(pakai cara),besok di kumpul

2. ∠ BOD = ∠AOD + ∠AOB
     180 = AOD  + 55
     AOD = 180-55
    AOD = 125°

    AOC = AOD + DOC
   180 = 125 + DOC
    DOC = 180-125
    DOC = 55°

    BOC = 360 -(AOD+AOD+DOC)
    BOC = 360 - (125+55+55)
    BOC = 360 -235
    BOC = 125°

3. ∠AOD = 90°
     3a+2a+a = 90°
     6a = 90°
      a = 15

∠AOB= 3a = 3×15 = 45°
∠BOC= 2a = 2×15 = 30°
∠COD= a =15°

5. ∠AOB = 180°
    30+35+x+35 = 180
     100 + x = 180
     x = 180 - 100
     x = 80°

∠DOB = x + 35° = 80 + 35 =115°

semoga membantu ^^