<DRN = 112LRN; <DRL=100°; <DRN=?

∠DRN = 11 * ∠LRN

Пусть ∠LRN = x. Тогда ∠DRN = 11x

∠DRL + ∠LRN = 180° (смежные углы)

10x + x = 180°

11x = 180°

x = 180°/11

∠LRN = 180°/11

∠DRN = 11 * (180°/11) = 180° - ∠LRN

∠DRN = 11 * 10° = 110°

Ответ: ∠DRN = 110°