If in a triangle ABC, angle A+ angle B = 105° and angle B + angle C= 120°, then angle B is? My attempt - Angle A + Angle B = 105° ..... (1) Angle B + Angle C = 120° or Angle C = 120° – Angle B ........ (2) Now, Angle A + Angle B + Angle C = 180° (Angle Sum property of a triangle) or 105° + 120° - Angle B = 180° (Substituting values from (1) and (2)) or 225° - Angle B = 180° or Angle B = 225° – 180° = 45° I am doubtful of my solution. Can you please help me determine if I've solved it the correct way? I know it's a simple question, still silly doubts. Thanks!

If in a triangle ABC, angle A+ angle B = 105° and angle B + angle C=

1.	If in a triangle ABC, angle A+ angle B = 105° and angle B + angle C= 120°, then angle B is? My attempt - Angle A + Angle B = 105° ..... (1) Angle B + Angle C = 120° or Angle C = 120° – Angle B ........ (2) Now, Angle A + Angle B + Angle C = 180° (Angle Sum property of a triangle) or 105° + 120° - Angle B = 180° (Substituting values from (1) and (2)) or 225° - Angle B = 180° or Angle B = 225° – 180° = 45° I am doubtful of my solution. Can you please help me determine if I've solved it the correct way? I know it's a simple question, still silly doubts. Thanks!
Answer» If in a triangle ABC, angle A+ angle B = 105° and angle B + angle C= 120°, then angle B is? My attempt - Angle A + Angle B = 105° ..... (1) Angle B + Angle C = 120° or Angle C = 120° – Angle B ........ (2) Now, Angle A + Angle B + Angle C = 180° (Angle Sum property of a triangle) or 105° + 120° - Angle B = 180° (Substituting values from (1) and (2)) or 225° - Angle B = 180° or Angle B = 225° – 180° = 45° I am doubtful of my solution. Can you please help me determine if I've solved it the correct way? I know it's a simple question, still silly doubts. Thanks!