Answer:
4th option
Explanation:
The sum of the 3 angles in a triangle must equal 180°
(1) 60 ° + 80° + 80° = 220° ≠ 180°
(2) 90° + 90° = 180° ( with only 2 angles, no third angle
(3)
obtuse angles are greater than 90° but less than 180° , so their sum would be greater than 180°
(4) 55° + 60° + 65° = 180°
option 4 is the correct condition