∠ABM = 100°
∠CBK = 155°
∠KBM = ?
∠ABM + ∠CBK + ∠KBM = 360°
100° + 155° + ∠KBM = 360°
255° + ∠KBM = 360°
∠KBM = 360° - 255°
∠KBM = 105°