INI GMN YAAAAAAAAAAAAA
Jawab:
Penjelasan dengan langkah-langkah:
∠BOC = 90°
∠BOC + ∠AOB = 180, maka
∠AOB = 90°
karna ∠AOB = 90°,
maka
AO = BO
∠OAB = ∠ABO
∠OAB + ∠ABO + ∠AOB = 180°, karena ∠OAB = ∠ABO, maka
2∠ABO + ∠AOB = 180°
2∠ABO + 90 = 180°
2∠ABO = 180° - 90
2∠ABO = 90
∠ABO = 90/2
∠ABO = .....°
