Question

given: two angles are supplementary Conjecture:they are both acute angles

Answer 1

Supplementary angles: Two angles are supplementary when they add up to 180º.

Acute angles: They are less than 90º.

So, for two angles to add up to 180º, we need two right angles(90º), or one obtuse(>90º) and one acute(<90º). So this conjecture is incorrect.