bantu jawab ya kak no 23

∠ACD + ∠DCB = 180°
(5x - 30) + (2x + 60) = 180
7x + 30 = 180
7x = 180 - 30
7x = 150
x = 150 : 7
x = 21,43

∠DCB = 2x + 60
∠DCB = 2 × 21,43 + 60
∠DCB = 42,86 + 60
∠DCB = 102,86°

Jawaban paling mendekati: D. 100°