(i)
ΔABC में,
∠A = 3x°, ∠B = 60° तथा ∠C = x°
∠A + ∠B + ∠C = 180°
3x° + 60 + x° = 180
4x + 60 = 180
4x = 180 – 60
4x = 120
x = 30°
(ii)
ΔABC में,
∠A = 2x°, ∠B = 3x° तथा ∠ACD = 115°
∠ACD, ΔABC के लिए बाह्य कोण है|
∠ACD = ∠CAB + ∠ABC
115 = 2x° + 3x°
5x° = 115
x = 23°
