Question

Which of the following could not be the set of interior angles of a triangle ?

• A. 80°, 50°, 50°
• B. 90°, 45°, 45°
• C. 70°, 55°, 45°
• D. 178°, 1°, 1°

Answer 1

The correct option is C 70°, 55°, 45°

We know that the sum of interior angles in a triangle is 180°.
So, if the sum of any set of interior angles is 180°,then they can be the angles of a triangle.
Adding all the given sets of interior angles, we get
80° + 50° + 50° = 180°
90° + 45° + 45° = 180°
70° + 55° + 45° = 170° ≠ 180°
178° + 1° + 1° = 180°
So, the angles 70° , 55° and 45° cannot be a set of interior angles of any triangle.