mau nanya dong kak ttg lingkaran smp

CAO = 2x
ABC = 3x
ACB = 90° ( Menghadap tali busur )

maka :
CAO + ABC + ACB = 180°
2x + 3x + 90° = 180°
5x = 90°
x = 18°

ADC = ABC ( menghadap busur yg sama )
ADC = 3x
= 3×18
= 54° (C) .